EquiSpirit's website is the best I've found for trailering advice / tips. 
Below are a selection of informative articles that are "must reading" if you are traveling with your horses.

1. New! - Towing Your Horse Trailer Safely to Your Destination
2. Choosing a Horse Trailer From the Horse's Point of View
3. Choosing a Tow Vehicle - It's All in the Numbers
4. Tips for Driving Safely with Your Horse Trailer
5. Emergency First Aid Kit
6. Editorial: The Rise and Possible Fall of All-Aluminum Horse Trailers
7. How do I know what size trailer will best fit my horse?
8. Don't Go On the Road Without It! - Emergency List
9. Purchasing the Right Horse Trailer - From the Horse's Point of View
10. Tow Vehicles - Which is Right!
11. Turning Radius for Horse Trailers
12. How to Turn While Towing a Horse Trailer
13. Backing Up Your Horse Trailer
14. Knowing How to Maintain Control When Towing
15. Aluminum vs. Steel Horse Trailers - Which is Best?
16. Debunking Trailer Myths and Half Truths
17. How Federal Motor Carrier Safety Regulations Affect Horse Trailers.
18. Important Terms to Know
19. Driving Your Horse Trailer
20. Horse Trailer Safety Check and Yearly Service
21. Advantages of Bumper Pull Horse Trailers
22. The Early Warning System - A Step Towards Insuring Horse Trailer Safety

1) What kind of brakes do I need on my horse trailer and why?

2) What is a breakaway brake?

3) Are safety chains really necessary?

4) Why are people getting away with hauling with illegal equipment and really scary looking trailer?

5) Do I need a logbook, medical card, or commercial driver's license?

6) What is the difference between GVW, GVWR, GCVWR, and GW?

7) What is Unladen Weight?

8) Why is it important to know the GVWR or the GW of my vehicle and trailer?

9) Should I stop at weight stations?

10) What kind of hitch do I need for a tag-along trailer?

11) Is a gooseneck trailer better than a tag-along?

12) What are the most important things I should consider when looking for a new trailer?

13) How do I know I am getting the right tow vehicle for my horse trailer?

14) What are the best construction materials for horse trailers?

15) What should I look for in a used trailer?

16) Are sports utilities and cars adequate to pull trailers?

17) What is the proper way to have weight distribution bars installed on your trailer tongue?

18) How do I use a a weight-distributing hitch?

19) How far should one travel before stopping for a rest and checking the horse?

20) When hauling one horse in a 2-horse bumper pull straight load, which side of the trailer should he ride on (in the US)?

21) What are the definition of terms like a coupler, undercarriage or chassis?

22) When hauling a horse trailer with living quarters with a 1 ton truck what are the advantages of 4 vs. 2-rear wheels?

23) Are fiberglass roofs common and are they recommended?

Thanks to Tom and Neva Scheve
The owners of EquiSpirit, Tom and Neva Scheve, literally wrote the book on horse trailers — The Complete Guide to Buying, Maintaining, and Servicing a Horse Trailer. Read it!

KCW
karl1952@email.com

Horse Trailer Floorboard Safety Check
Here's how to clean, inspect, and condition your horse trailer's wooden floorboards.

Restore, Repair or Replace? This process won't protect floorboards that have already begun to rot from deterioration, nor will it restore rotten wood. If your trailer's floorboards look or feel spongy, are pitted, or sag when you load your horse, you probably need a new floor. Call your trailer dealer for repair guidelines, or buy a new trailer altogether.

Here's What You'll Need

                     Steamed distilled turpentine

                     Boiled linseed oil

                     4" polyester paintbrush

                     64-oz. glass measuring cup

                     16-oz. can of paint thinner

                     Hammer

                     Broom

                     Wire brush

                     Garden hose with spray nozzle

                     Putty knife

                     Whisk broom

                     Dustpan

                     Flashlight

                     Screwdriver

                     1-gal. plastic milk jug with lid

                     3-lb. coffee can

                     Funnel

                     Towel

Procedure

Step 1. Prop open your trailer door and windows for ventilation. Pull out the mats. (If the mats are tacked down, pull out the tacks with a hammer, or lift straight up at the front corners.) Briskly sweep the floorboards with the broom. Then, with the wire brush, scrub manure stains and areas where water and dirt tend to collect-usually along edges and doors. With the hose's spray nozzle, rinse out the remaining dirt and debris.

Step 2. Remove from your tack compartment any carpeting or other covering to expose the wood flooring. Use the putty knife or wire brush to remove debris and mildew, then clean up the residue with the whisk broom and dustpan. Pan the flashlight down walls to check for leaks. If you spot one, make a note to get it fixed.

Step 3. With the screwdriver, probe into the floorboards. If you can easily insert the screwdriver into the wood, you've found wood rot. Pay special attention to any areas where water remains as a result of your rinsing efforts; places where water collects tend to rot more quickly. Be sure to carefully check around knot holes, dented or warped areas, and weathered spots. In your tack compartment, pay particular attention to areas where water may have collected from leaks.

If the soft spots are quarter-size or smaller, you'll be able to clean out the rot and save the board. (See Step 5.) Make note of larger soft spots, so you'll know which boards to replace.

Step 4. Slide the putty knife's thin blade into any gaps between metal and wood; metal and rust corrode wood. Carefully check around screws, bolts, and nails. Check door thresholds and places where walls, partitions, and feed bunks are attached to the floor.

Step 5. Stull using the putty knife, go back to any small soft spots you found, and dig out the rot or any soft wood particles. Use the wire brush to remove any remaining wood particles. If the soft spots don't dig out easily, leave them; the wood is still sound.

Step 6. Prepare the wood conditioning mixture. You'll need the milk jug, measuring cup, coffee can, funnel, linseed oil, and turpentine. In the milk jug, mix 2 parts linseed oil to 1 part turpentine; use the funnel for ease of pouring. Most two-horse trailers take about 3 quarts of mix for two coats of treatment. For this amount, mix 2 quarts (8 cups) linseed oil with 1 quart (4 cups) turpentine. Put on the lid and shake. Pour the mixture into the coffee can.

Step 7. If any standing pools of water remain on the floorboards from rinsing, dry them with a towel. With the paintbrush, apply a generous coat of the wood-conditioning mixture. Start at the front of the trailer, and work your way to the back. Give special attention to dents, knots, screws, bolts, nails, and areas along the walls and near the door. Treat the tack compartment's floorboards similarly. Allow the floorboards to absorb the moisture, then apply another coat. Repeat until the wood no longer absorbs the mixture.

Step 8. Allow the floorboards to dry completely, leaving the trailer doors open and the mats out. When the floor is dry, put the mats back in, and close up the trailer. (If you plan to store your trailer outside until spring, leave the mats out; otherwise, moisture will condense under them, hastening wood rot.)

Step 9. Clean the paintbrush and coffee can with paint thinner. If you have leftover wood-conditioning mixture, label the milk jug, then store it in a cool, dry place. (To dispose of the mixture, check your local ordinances for hazardous-material disposal guidelines.) Repeat this project every 6 months.

Thanks to Tom and Neva Scheve
The owners of EquiSpirit, Tom and Neva Scheve, literally wrote the book on horse trailers — The Complete Guide to Buying, Maintaining, and Servicing a Horse Trailer.

KCW
karl1952@email.com

I noticed that the article about aluminum trailers which contained much incorrect information, was authored by a steel trailer manufacturer. I would not consider their slanted comments viable or pertinent to the thousands of satisfied users of aluminum trailers. The whole article was so slanted and biased that it became totally erroneous and irrelevant.

If this is the best advise that is available, and the public believes that just because it was published, we should believe it as being true, then we are all in a whole bunch of trouble. This information is certainly not the "BEST" that is available.

BOL  Gard