There are a whole lot of threads around on the forum of people talking about their splits- in fact, there was a "Splits in 2015" thread that sort of died somewhere around August, but was quite full of interesting tips.
Mainly, you have to check to see if your hips are in the right alignment. I know Veena put out a video with some tips about that some time ago (sorry, time for me is a weird thing, it could have been one or two years ago?) and it would be worthwhile to check out, specially for your second question.
Mainly, you want to be as warmed up as possible while stretching, and being gentle. You should not feel pain while training for flexibility, just a sort of discomfort. Take it slow, and don't push yourself too far.
Alethea Austin, in her Pure Splits DVD, talks about how it took her 5 years or so to achieve her splits in any way. People are all very different, in strength and flexibility, in what their bodies will allow, or take to easily. You may see a faster result in achieving your splits, but you might not.
Best advice is to be patient, and also consistent.