Cutting out backrounds from images

Well I have looked over the internet to find a good tutorial to cut out specific parts of pictures from a backround but have not found any that were very helpful. If anybody could hook me up with a good one or just tell me how in this thread I would appreciate it alot.
Current image programs I can use are Adobe Photoshop 7.0, Adobe ImageReady 7.0, and Microsoft Paint.

Also while we are here does anybody know how I can take a screenshot from a movie in DivX?

Sorry if this is the wrong forum for this.

There is no special way, just using magic wand, lasso, then quickmask mode. Its better to work from the outside in, then invert the selection.

Ok thanks. That is what most of the tutorials out there told me but I thought there must be some special way because some people are just so good at it. Guess I gotta practice on it.