i have a 2yo paint gelding, artie.  i am new to the do-it-yourself training thing. i have worked with trainers before with green horses, but never installed the buttons myself.

artie and i have been working on ground manners. he is an absolute DOLL! ive never had any issues with him at all. never nipped, kicked, reared, bucked, nothing. hes got quite the personality and is quite curious. ive also saddled, bridled, and sat up on him once, and also had my sister walk him around a few steps while i sat on him. never even got a reaction!

i was wondering when is the best time to start riding him. i was going to wait til the spring to actually get on and start walking around a bit. he'll be a few months shy of 3 by then.

what do yall think?

As an up-and-coming vet you should know this  but then again I've seen vets wreck horses just like regular folks.

I would say the age at which you should start a horse depends on the horse.  You shouldn't start a horse before they are mentally and physically able to carry a person and handle the extra weight.  Also some horse don't mature mentally until after 3, in fact some blood lines are known for this.  The breed and bloodline can also tell you about how mature the skeleton is at 2 and 3 years of age.  When in doubt shoot some film!  X-rays are the absolute answer to the growth question.  Coordination is a big thing, some 2 year olds can hardly handle themselves much less extra weight way up on their back.  Riding one of these can scare the crap out of a person, you always feel the next turn could be the last...it's similar to riding a blob of Jell-O.  You can't collect them because they don't even know where their feet are, it's down right impossible to ride them until they figure out how to move everything with control.

All of this said, I have bought horses that were "futurity" horses and all was fine until the horse turned 6 and they fell apart physically.  I've ridden horses that were "futurity" horses and were fine until their late teens and beyond.  I think bloodline has more to do with soundness than most, but you can ruin a great horse by jumping the gun too!

Your horse isn't by chance an Artful Move is he?  If so I say wait until he's three just based on his potential growth.

Agreed- some horses are more ready for training than others at the same age. I liked to wait until they were 3- then progress at the horses speed. If they are learning the lesson, move on to the next and stay there wuntil that lesson is learned. Sometimes its takes a few weeks, sometimes a few days. I like to let the horse figure out how to balance themselves, soften and lighten to my hands and seat before moving on. There days when everything is perfect, then the next days I wonder where the heck that horse went....so you just work on simple stuff, put them away and try again another day. Just ask and expect little. Release of pressure is the reward.

Now most horses are great on the ground with pretty much everything but don't expect that when your on their back. Its a whole new ball game. Take the same appraoch- ask, be paitent ,then reward for the smallest thing. Your horse might never buck or rear but it can happen so don't be shocked. This is a long term process that never really ends much like your career in vet school. YOu aren't going to learning everything in day,week or month so don't expect a horse to as well.