There are several types of window treatments that will work for multi-paned windows. It really depends on your personal preference and the look that you are trying to create in your home. You will just have to measure your windows before you go shopping.
Window treatments for bay windows can be found online at HGTV. At HGTV they have put together what they think are the best 6 window treatments available. Also one could check Wikipedia for information.
A great place for information on window treatments is Calico Corners. Check out their website at www.calicocorners.com/category/custom+window+treatments.do for information on draperies, shades and more.
Opaque privacy glass is the best glass for bathroom windows. Block glass also works great depending on the window. If none of those work, a regular double paned window will suffice and then you can put window treatments in the window for privacy.
Sierra Trading Post has a great article on choosing window treatments based on your windows, decor and needs. You can read it at http://www.sierratradingpost.com/lp2/window-treatment-guide.html. One of my favorite sites, Dummies.com. has an excellant guide for choosing window treatments. You can see their advice at http://www.dummies.com/how-to/content/using-curtains-and-draperies-in-your-home-decor.html.
Horizontal blinds (for large window treatments) on the other hand, such as cellular shades and wood blinds, work best on windows that are taller, so you can find them at Lowe's or Home Depot.
I would use customized window treatments for a picture window.
There is a lot of information on the treatment and decor of bay and windows that can be found. This information may help you out: http://www.bhg.com/decorating/window-treatments/basics/bay-and-bow-window-treatment-ideas/
Get window wallpaper with UV protection.
Double pane windows are very energy efficient. They provide an extra layer of protection from the cold. Shades or heavy drapes also keep out the hot sun and the cold in the winter. If you can't afford double pane windows, window treatments can also help save energy.
You can get custom window treatments at affordable prices at your local Lowe's or Home Depot. They have great selection.
Windows XP Ultimate if you're racist.
A lot of people claim that old newspapers are the best thing for cleaning windows. Vinegar and water is a good home recipe for window cleaner. For really large windows, a squeegee works best. Be sure to use ammonia-free window cleaner for tinted windows and other specialty glass.