How long have you been using an SLR
There are 2 answers to that question.
I bought a 35mm SLR (Canon FTb) in 1973 and used it until the shutter failed in 1987. I had 2 lenses - don't exactly remember what they were - probably a 50mm and I seem to remember the 2nd lense as a 135mm. I wasn't a particularly involved hobbyist, just someone that wanted to take better snapshots. When the shutter failed I switched to 35mm point and shoot cameras.
I went digital in the late 90s and had a series of point and shoot Canons. Last November I once again decided I wanted to be able to take better snapshots. I was going to buy a G11 and boldly announced to this group my intentions - the comments that came back pointed me to a number of websites discussing the physical characteristics of the image sensors that Digital Cameras use and the distinct advantages that larger sensors have over smaller ones - I decided to take the same $500 that I was going to spend on the G11 and buy the Rebel XS instead. I'm very glad I did.
how many different lens did you use
Although I have 3 lenses I take 95% of my pictures with 2 of them. Probably the majority of the pictures I take are with the 18-55mm Kit lens, virtually all of the remainder (since April when I got it) are with a 70-200mm F4L lens I bought for the trip to France. Be careful buying 'L' lenses - the rascals are so good they make you lust after more of them (I'm saving up to replace the kit lens with a 17-55mm F2.8 which is supposed to have 'L' quality optics - at a mere 10 times the price of the kit lens

). And I also have a 50mm F1.8 that works quite nicely for portraits and such. It is a very sharp lens if you use it at apertures of F2.8 and up (and at $100 brand spankin new has got to rank right up there in terms of value).
On Smugmug you can see which pictures were taken with which lens by clicking on the 'i' on the pop-up menu that appears when you hover the mouse over a picture.
I've found the XS to be a very nice learning tool capable of excellent pictures with good glass and frankly after having tried out the superlative 5D MKII in the store (with a beast of an F2.8 zoom on it) I ran back to my XS like a scalded cat. At just over a pound with the kit lens the XS is a really easy thing to have with you all day - which helps me fufill the first rule of photography - "F8 and be there" - or to paraphrase - to get the shot you have to be there and have a camera.
I really recommend going to an camera store, picking up an XS, playing with the menus, shooting a few shots with it in the store, at least looking at them on the store's computer (or better yet bring your own SD card and take it home to look at them) AND if at all possible do the same with a Pentax Kx and a Nikon.
All basic DSLRs do a good technical job I expect - and you might be surprised at how much different they feel - and how menus work may drive you bonkers on one camera but seem perfectly understandable on another. For example I love how the XS fits my hand but there are people who think it is small and hard to hold onto.
Welcome to the DSLR zone, good hunting.