Best book for SAT prep is the Official SAT Study Guide by CollegeBoard themselves. Has 10 full length practice tests that are no different from the actual test in anyway. Best book for practice IMO. If you need help with test-giving tactics refer to Princeton Review (it has 4 practice tests that are also pretty good).
And for a word list, refer to Direct Hits Volume 1 and 2. It's not available in Pakistan, but you can download a scanned copy off the net and print it (it's only ~20 pages). It's the most concise and relevant list I've come across.
Barron's on the other hand, is useless. Don't bother with it.