Where will the shower be held? In a home or restaurant, or other location? Is this a "traditional" type of person/shower, or the "bachelarette party" type???
Games:
* We always play one where everyone gets a name tag with something wedding related. Of course, the brides name tag says, "bride," and you would have other things like maybe "maid of honor" "bridesmaid" "bouquet" "ring" "garter" and so on. You can do this many ways, but what we do is tell everyone to bring lots of quarters, and we buy some sort of piggy bank, and everytime someone calls someone by their real name, they have to put a quarter into the bank. At the end of the party, the bride gets all the money in the bank. The other way to play it is if you call someone by thier real name, you have to give them your name tag, and at the end, whoever collects the most name tags wins a prize.
I need to think a bit for other "tame" games.
I have ideas for more "risque" games too, but I'll post them only if it's going to be that kind of party.
A kind of Hawaii tradition is to have the bride unwrap her presents gently, keeping the paper and ribbon in tact if possible. After they're unwrapped, everyone uses the wrapping to "wrap" the bride and make a gown out of the paper (and if possible, the veil too). With a paper plate, holes are punched in it, then the ribbon strung through to form a bouquet.
Decorations:
Does the bride have a "theme" or certain wedding colors? The main thing is favors. The easiest thing to do is to get some kind of wrapped candy (Hershey's kisses, or Dove has wrapped candies too). You could either wrap it in some nice netting and tie some fake flowers (the kind with the wire step) around it, or one shower we did we had some little plastic swans, put the candy in it, and wrapped the entire swan with netting. If it's a large party at a restaurant with tables, you could also make centerpieces. You should also be able to find ready-made signs and things if you're not inclined to make your own.