Matching horses and owners

A large part of the problems I see with people not being able to enjoy their horses and the riding experience, is poor matches of horses with people. If you are a new rider, it's not a good idea to get a young, inexperienced horse. You will not have the know how or the confidence to help the horse learn his job and will only confuse him. Then he will get nervous and that's a recipe for disaster. I see so many people who overestimate their ability both to ride and to train horses. Who loses? you both do, but often times it's the horse who gets the short end of the stick and gets blamed for bad behavior when he's only being a horse.
A beginner rider should look for an experienced quiet horse that has been there, done that so you can learn how to ride and care for a horse. You will both enjoy the experience much more. When you get more experience, you can start getting into more horses that need teaching and training.
Another common mistake I see is choosing the wrong breed of horse for the activity you are involved in. for example, as a general rule, quarterhorses and drafts are calmer than say arabians. Gaited horses are smoother than non-gaited. If you like to walk the majority of the ride and do a little trotting but not much more, an arabian may not be a good choice as they are more prone to want to move faster and get impatient if made to walk the whole way.
Conversely, if you like to do lots of trotting and cantering, a draft horse will be worn out after a couple hour ride. So it's impotant to know your riding preference and pick a horse that matches your needs. Once you have some experience, you'll find that with work and patience many horses can do many different tasks and activities, but you need to understand horse behavior and breed tendencies.
Also, don't try to train a horse if you are not absolutely sure you know what you are doing. You will only cause problems that someone else will have to fix. Many people think they can train horses and many are very good. However, there are many who consider themselves trainers who leave much to be desired. I train my own horses, for trails, lessons, trailering, and most basic things. However, I would not try to train my horse for dressage or show as I have no experience in either and would only ruin my horses chances of reaching his full potential. I would look for a reputable trainer for something like that. You must know your limitations. I also conceed that my girlfriend is a much better trainer than I, but I can out ride her! ha ha, just kidding honey.
Anyway, picking the right horse is very important for both owner and horse. There is always someone with experience who will help you. Horse people are a great group as a whole.