Responses to Preempts
Good For Him. If your partner made a weak preemptive bid, good for him. He has shown you exactly what he has and won't bid again -- count on it.
All At Once. Bid as high as you're willing to go all at once if you think there's going to be competition, for example, if the intervening hand doubles. Don't wait until they've found their nice fit in Spades before sacrificing at 5 Clubs after your partner's 3 Club opener.
Bid it right away. Sometimes, you'll get away with it. Sometimes you won't get doubled. Sometimes they'll end up in the wrong contract. Sometimes they'll take the push and go off one.
But if you wait until they know what they have, you've just lowered your odds a lot. They'll always figure it out. Besides, it's only a game -- and not for money at that!
Don't even think about changing suits. The one time in ten your long weak suit is better than your partners won't make up for the 8 bad results you'll get changing suits, and you'll soon lose good partners, too.
Rarely, you'll have a good hand and want to try for game -- fine, go ahead and bid it. But don't plan on your partner bidding again voluntarily -- just do it.
(For Weak Twos -- not higher-level preempts -- there are some 2NT response conventions that ask opener for more information, designed to get to 3NT if you have stoppers and can visualize 6 tricks in the openers suit . Ogust is one such convention, but they aren't covered in this book)