One of the single most helpful things I gave my guests was a wedding map. I used YAHOO! maps to make directions and put them in the OOT gift boxes in the hotels. Later someone told me about a website that you can go on and make your own customized wedding map - with icons, directions, pictures... It's called weddingmapper (appropriately named). You can also see wedding maps from other brides to help you plan you wedding.
I just wanted to share. I'll share some more tips later.