Should I shoot in RAW mode if I like to edit my pictures?

Because whenever I edit my pictures and then make a slide show on iMovie they look really bad quality. I'm useing a Nikon D5000 and a macbook pro 15" and I use Aperture 3 to edit.

Yea, RAW is for people who edit there photos afterwards.
so if you know that's what you're going to do, shoot in RAW.
just make sure you have a good memory card ( someone told me if your card has a 10 with a circle around it and it's 4GB you'll be able to get i belive about 130 RAW pictures, if i remember correctly )

Remember each camera make has their own RAW software. My guess is your presentation software doesn't understand your Nikon RAW images. Yes edit in RAW if you have the memory and the other wherewithal to do so but then convert to jpg to display. Remember the web standard is 72 dpi also where your RAW images may be 300.

Adobe Lightroom3 has the most features that make processing RAW an advantage.

You can setup custom white balance, match the image files to the camera and lenses you use and a whole number of other adjustments to produce high quality JPEG or TIFF files which you control, NOT the camera

Shooting in RAW provides much more versatility in post-processing. I've only recently begun shooting in RAW instead of JPEG and I'm really enjoying it. I edit with LightRoom.

I won't chime in to the choir here and say "Depends" at first.

You will have to use some real RAW processing software to get better results, as the in camera conversion to jpg already does a lot of things that you won't get done with other software, such as picasa. E. G. The D5000 already automatically corrects some lens distortion and chromatic aberrations. If one's software can't do this, then one is usually better off shooting jpg.

Aperture 3 will be able to do that though, so the final answer is "yes".