What is the best mode to set your memory card on digital cameras'?

I have an Olympus EVOLT E-500 digital camera. I bought a XD picture card for it. There are different modes it allows me to set it on. HQ, SQ, RAW+SQ,RAW+HQ, RAW and TIFF. Can anyone explain the difference in these settings? I've noticed that in HQ mode I can get 1036 pictures and in TIFF and RAW the number of pictures are greatly reduced to around 100 pictures. Any advice you can give me is greatly appreciated to help me better understand the differences. I am shooting a friends wedding (nothing formal) but I wanted to get nice quality photos' but also the maximum number of photos also. Thanks

There is no JPEG setting. I'm just trying to figure out what is the best mode to use to get the best quality picture.

The JPEG settings are the HQ (HighQuality) and SQ (StandardQuality). Until you get used to getting your exposure dead on, shoot RAW+SQ. That way you will have a JPEG image to view in your file manager (for editing out the out of focus or just boring images) and a RAW to deal with exposures that are slightly higher or lower than perfect. After you have done your first edit, you can show the JPEGS to your friends and when they order actual images you can do the conversion of the RAW images into TIFF or HighRez JPEG images (which ever your photo lab prefers).

For the wedding, be sure you have a flash unit that is compatible with your camera.

xD cards are very cheap right now, so get a couple of 2GB cards ($18 each last weekend) to add to what you have. You don't want to run out of "film" in the middle of wedding. Shooting a lower resolutions will give you images that will be great for use in email and maybe 4x6 inch prints, but nothing much larger.

It's almost always a trade off: Max photos or max quality. Only you can make that decision.

Is there a JPEG setting? This a compression format that allows you to store higher quality files in a smaller format. When you transfer the images from your camera or card, into your computer, when you make changes to the image and save, be sure to save to maximum file size, or else the image will degrade each time you do this.

RAW and TIFF suck down gobs of card space without significant benefits.

Put it on the highest quality JPG setting.

Just be sure your white balance is properly set.

The most important thing at weddings is lighting. Be sure to use a diffuser on your flash and bounce it if you can.