My Reno was unworked at the rescue for about a year, then for almost another year after coming home with me. My trainer and I started with just being around him, all-around loving on him to get him used to everything and building trust. One specific thing we did was lead him around the indoor arena so he could see things and become familiar with it. I was surprised he didn't spook at the huge, menacing-looking tractor. After a few months we started lunging him...slowly. He gradually caught on and did rather well. Now (10 months after I adopted him) he's under saddle, learning how to be something other than a racehorse. Currently getting him used to actually having weight on him...he doesn't understand when people post (or attempt to...floaty trot lol). His training will progress and we will eventually compete in dressage (most likely lower levels...cause I fail that way). I'm also going to reply to your feed thread.
I didn't buy my guy straight off the track but the man who sold him to me didn't do much with him so he still had the same mental state as one fresh off the racetrack.
I started him with tons of roundpen work before I even got on him. Making him learn my verbal cues for walk, trot, canter, whoa and easy. I did have a trainer to help me out a few times a month (still do) so I do recommend one if you haven't brought one along before. Start slow and PATIENCE!!!! Teaching verbal commands has saved my butt too many times to count.
When starting under saddle be relaxed and do lots of circles, transitions, change of direction etc. They tend to get bored and wound up if they don't have anything to keep their minds occupied. My boy loves it when I talk to him while riding it seems to soothe him and he listens a lot more to my voice than anything else.
Hope this helps!
I don't give them lots of time off. In fact I often ride the day they arrive. But, I don't think either way is better. Do what you want.
I give them a chance to move and explore under saddle at a walk and trot. Lots of trotting over uneven ground to condition them to what they'll be doing and let them 'find their feet' so to speak. They are busy thinking about staying upright and sightseeing. They seem to enjoy it.
I often ride in a pelham, use only the snaffle rein, usually, but have the curb if I need it.