Hi R. - you've gotten lots of great advice here, and you may be feeling just as confused as ever. What I've found on all of the sleep books (and I've seriously read every one of them), is you can find proponents and opponents for every style of "sleep training". No cry, check-and-console, let cry, Ferberize, extinction method - you name it, I've read it!
Either way, all kids are different. Ours had reflux and as such, spent the entire (and I mean all day) first four months crying. He never had a "fuss" in him - he was either happy or screaming. So it was really tough for us to try to let him "self soothe" because he went from happy while holding him, to screaming as soon as we lay him down. As a result, we definitely developed some sleep crutches we had to get rid of (he's 9 months now) and though it was tough, I think there are sometimes not complete clear answers on the "right" way to go about sleep training.
Our son was a 30-minute napper on the nose. I tried EVERYTHING to get him to lengthen his naps. I do like Dr. Weissbluth's book - he's the one that suggests putting kids down within an hour to an hour-and-a-half after they wake, and then only two hours of wakefulness in between each nap. We followed this rule, and it helped to keep the melt downs to a minimum. But it took months until he started napping longer. If you get four hours per day, you're lucky! We got three half-hour naps TOTAL!!
The only thing that finally worked for us is we invested in a baby hammock. There are several brands out there - we got the Amby just because one of my friends had one and liked it. We would put our little guy in it and bounce it while he cried himself to sleep. It wasn't total self-soothing, but it was one step above falling asleep in our arms. Then, when he woke at the half-hour mark, we'd go in and bounce him again until he fell asleep - usually for one more half-hour, and then he'd be up. Gradually, though, he quit waking up at the half-hour mark and slept for an hour straight, but this wasn't until about 6 months.
I know it's still a crutch and if you CAN teach your daughter how to sleep on her own, and get herself back to sleep after she wakes prematurely, you will be so much better off. But I also understand how tired you feel and how desperately you are aching for some of your own time! So, go with your gut. If you can, even pick just one nap a day (Dr. Weissbluth recommends the first nap of the day) to let her practice sleeping on her own. Then for the other naps, you can do whatever to get some sanity. If/when she's sleeping well on her first nap, you can do the same routine for the other naps.
Our son was taking three naps a day (like I said, of only a half-hour each) until he was 6 months old.
Good luck and I totally feel for you!!