If your after an idea of the training of some of the actual action, A guy named keith Fennel wrote a couple of books called Warrior Training and Warrior brothers. One is about the Selection course and ongoing training, the other is about some of the actual missions. He's note the greatest wrighter or anything but its an insiders account of what goes on. check it.
EDIT; the dude is ex SASR by the way
Read Warrior Training as well. Quite a good read, and gives you a good idea of how hard it is just to get a go in the selection course, not to mention how hard it is to actually pass the test.
Along with that, I've read 'Amazing SAS: The inside story of Aust Spec Forces' & 'Soldiers Without Borders' by Ian McPhedron which gives you a pretty good idea of what the SAS does and how they do it (including selection), and also what they do after they leave the army.
If you haven't already read these books, they would be a good place to start. I have become quite fascinated over this section of the Army, and am reading quite a few of the books about them (and their British counterparts).
From what I have read in the books, many of them don't like to talk about their experiences, but it you do happen to know someone, you may be able to extract some information from them (although you might want to give confrontation or torture a miss, they are highly trained!). At the end of the day, these guys are the cream of the crop, and are only used in the most delicate of scenarios. The work they do is pretty well guarded (even to family), so they may not be able to talk much about what they did, but only give you an idea of what to expect if it is a course you want to pursue.
What I'm saying is don't be suprised if you can't find anyone that has been in these regiments. They are few and far between. Even if you do find someone, it might be like drawing blood from a stone asking some questions. The best bet would be to read up about them (especially books written by ex-SAS guys), like the ones above, and going from there.
EDIT: Watch the videos posted above. Will give you plenty of info. (Im sitting down to watch them now!)
