Here is a link to some sites that Equisearch has put together to give you a start on your research :-)
web page I first want to commend you for wanting to do research before starting to seriously look for a horse. I second want to let you know that horses are individuals, and while animals of specific breeds may have a tendancy towards certain behaviors, any given horse can have ANY temprament. So, if a breed is described as "hot" (like an Arabian) don't assume that ALL Arabians are hot. Likewise, not all Quarter Horses are calm.
If you are seriously COMMITTED (and I put that in bold because it takes A TREMENDOUS amount of commitment to have and care for a horse), I urge you to take riding lessons with a trainer before you even begin to look for horses. Even experienced riders take lessons, because being a good horseman is a life-long process. Not only will lessons give you some skills that you will need to have a successful horse experience, it will also give you an awarness of the costs associated with horse ownership. In addition, your best bet in finding a safe, appropriate horse is to get someone to help you pick out the one that best suits your needs and abilities. A LOT of people unfortunately have horses that are not appropriate for them, either training or temprament wise, and it really takes away from much of the joys of owning a horse.
Good luck, and let us know how you progress!!