I think that most of the succulents I've kept have been pretty easy, as long as you only water when appropriate. For most of my plants, their growth season is in the fall so, they get more regular water then but still probably only 1x/week. The rest of the year, I tend to water when I remember, when probably ends up being 1x/every 3-4 weeks.
Most of them let you know when they need water by getting shriveled (at least the lithops) and too much water causes them to look like they're going to burst, which they can if they're over watered. I haven't managed to do that yet but I've come close.
The only other important factor besides water is the soil. Everyone has a different mix that they use but sharp draining is important so, I use succulent soil and then add sand, pea gravel and gypsum.
If you're thinking of buying a few, I would recommend finding what you want someplace like Arid Lands
because they have a huge selection and lots of pictures of everything. I prefer to actually buy at Miles 2 Go
because his prices are quite a bit lower but his online catalog is much less user friendly. I've been very pleased with the quality of everything I've purchased from him.
So, kind of a long answer to a simple question.