The site for the Bahrain GP is
www.bahraingp.com, without the bh at the end. I have my tickets booked on the Turn 1 Grandstand, for me and the whole family. This should be a nice spot. Last year I went all on my own (my family had not arrived by then), and I sat on the University Stand. If you intend booking on the University stand, make sure that you're at least 15 seats away from the righthand side of the stand, and higher up than halfway from the front. Otherwise you'll be sitting in the sun during the afternoon. Last year the temp on race day was 42°C, but this year should be somewhat cooler, bacause it's one month earlier. I was cooked after the race last year.
Also make 100% sure that your exit/re-entry visa is in order. Sometimes you get a multiple exit/re-entry visa, but on the computer system on the causeway it is only entered as a single. This forced my friend to turn around at the causeway and go home last year!! Don't let such a disappointment happen to you.