www.sbp.org.pk is full of Financial gen. knowledge, i thnk they will upload Annual report 2010 by the end of this month. That report will help u alot. In the mean time u can read reports of 1st 3 quaters.
For other type of general knowledge English Newspaper are best source. Especially 2 months newspapers back from the test date.
I have experinace according to following break down. vary from test to test.
Airthematics 70%-100%
Algebra 10%- 30%
Goematry 0% - 10%. (Very rare chance)
U should have the knowledge of formula's reagarding Area and Volume of different geometric figures.
For English section Again Enlish newspaper and Barron's GMAT will b benefical.
Every bank have different pattern of english, u will recive sample paper before test from that u can hav idea of pattern of maths n English portion.
Now a days essay writting is not part of bank test, but if essay is comming in the test they will tell this thing in sample paper. so dont worry about pattern.
Wiah u good luck.