I would just like to preface this with, Uros rule 
There are a few resources that you should definitely read through. Deer Fern Farms and Urotopia (Doug Dix and Lindsay Pike respectively) are two great breeders that people on this board have repeatedly had phenomenal experiences with. There are a few others, but those are the ones I am most familiar with. I have mostly interacted with Lindsay Pike (www.urotopia.com), and would recommend him unequivocally for when you decide to get a Uro.
Doug Dix has the best information though:
http://www.deerfernfarms.com/Uromastyx_Index.htm
and directly to the caresheet:
http://www.deerfernfarms.com/Uromastyx_Care.htm
As far as housing goes, bigger is better.
At least once they get past the juvie stage. Minimum size imo for most of the Uro types is a 40 gallon breeder tank. I had an adult mali that lived fairly comfortably in one until he was about 6 years old, then I moved him to a 4ft x 2ft custom cage. He probably would have liked to have moved a year or so earlier though. If you go with an Egyptian though, they can get upwards of 3ft, and obviously would need something much larger as adults.
Substrate is a much debated topic. From what I have been reading, I think a dirt mixture (search the forum for substrate and there will be MUCH debate and description
)is probably the most natural. Many of the Uros are burrowers, and the dirt allows them that ability. However, it requires a lot of time and patience and playing around to get and keep a good dirt set up (at least it seems so). I keep mine on playsand, because they can still dig, though it is probably a little frustrating that they can't build tunnels and such.
I have had Uros for almost 10 years, and never regret the choice. A mali was my first lizard, and I now have an Egyptian.
From what I have read, Uros should be easier to keep than Chams, particularly since they are basically vegetarians, lol.
If you have any questions as you wade through the available info feel free to ask! This forum is a wealth of information, and has some people on it that have extensive experience with varous Uro types. 
Welcome!
Elizabeth

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1.0 Mali Uro Archimedes (May he rest in peace)
0.0.1 Egyptian Uro Zuberi Mosca Khu (Mosca)
0.0 Fish
0.1 Sulcata Minnie
1.1 Iguanas Flik and Loki
0.1 Newfoundland Jasmine (RIP)
0.1 Feline Winter
Indiana & Wisconsin