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 Acol Bidding page for some suggestions.
Acol Bidding - Responding to 2 NT
Points: 0 - 4
Pass (unless you have a very unbalanced hand and a long suit then try the suit at the 3 level).
Balanced Hand
Points: 5 - 10
Bid 3NT.
Points: 11 - 12
Bid 4NT inviting your partner to bid a slam with a maximum
Points: 13+
Bid 6NT.
Points: 17+
Bid 7NT if you hold all of the aces.
All of the above bids contain an element of risk and rely on average distribution of cards and points. You might prefer to be more cautious with the higher levels of bidding by trying a suit bid then using a slam convention (but you risk your partner passing your bid if it does not sound positive!).
Unbalanced Hand
Points: 5 +
Bid your best (preferably 5 card or more) suit at the 3 level.
Baron
An alternative to the suit bids above is to use the Stayman or Baron conventions.