I own a printing company. If I can help, let me know.
8.5x11 folded to 5.5x8.5 is a nice convenient size for booklets.
I would recommend Publisher over Powerpoint for page layout....and I'd recommend Serif PagePlus over publisher as a powerful low cost solution. You'll want to send a PDF file to the printer so they can (hopefully) print without many problems.
Are you looking for black & white, color? If you're looking for a printer feel free to ask for an estimate. I don't recommend the office supply store for printing, for a few reasons