These Help pages can be downloaded here with the Winning Bridge Shareware game for Microsoft Windows 98, ME, 2000 and XP.
If you would rather read a book, take a look at the Help Index page for some suggestions.
Second Bid
Partner Supported the Opening Suit (including no trump)
Partner Bid a New Suit
Partner Bid No Trumps over the Opening Suit
Partner Bid a Suit Over No Trump