Chosen Soldier is a good book - but dated - forget the G2 even about the jobs - you stated your goal is SF, step one is getting to SFAS, step 2 is getting Selected, step 3 is making through the Q course, step 4 is then learning what it's all about. You cannot understand it until you are on a Team and that's where you really learn.
No tips - go in wanting it, and be willing to sacrifice everything to achieve each 25m target. Nothing anybody tells you will be accurate from one minute to the next, much less from one class to the next - 99.99% of it is heart.
Quit friggin arguing and go do PT, Land Nav, then more PT and then read Go Rin No Sho, The Art of War, War through the Ages, and On Warfare (for a start) Your light reading could include the Dorsai series and some of John Ringo's stuff.