These Help pages can be downloaded here with the Winning Bridge Shareware game for Microsoft Windows 95+.
If you would rather read a book, take a look at the Acol Bidding page for some suggestions.
Acol Bidding - Opening
A balanced hand is any hand that has a Short Point count of 2 or less (i.e. no more extreme than two doubletons).
Pass
If the opposition have bid you should consider whether to Overcall.