You've written your novel, and if you're technically minded you might have used something clever like a spreadsheet to develop it. At this stage I'd say dump the computer. Rewrites HAVE to be a time when anything goes, when you're shuffling the cards around and anything could end up anywhere. If you use a spread sheet, you're changing one element a time. It doesn't have the same 'suck it and see' facility. There's an organic fluidity about using the cards: Take this one away, what does the novel look like? Put this one here, not there, or what about over there? This needs to happen before that - or does it? It's harder to experiment when it's on the computer, it all looks so neat and tidy and well organised. But it's got to get worse before getting better.
For some strange reason, when we edit on the computer screen we miss stuff. Print it out and mistakes and typos screech at you, practically circling themselves with red ink. Always, always, always print out your manuscript to do at least the final edit on paper.
3. Note taking
OK, this one has caused me grief because I really really really want an iPad and taking notes was one of the ways I was going to justify it to myself. But I know it doesn't work like that. A bit like re-drafting, notes are an organic form, the imaginative part of the brain working, not the technical bit. Snippets of info get saved - ideas for titles, snatches of dialogue, plot ideas (and shopping lists). Now you can put them all neatly into your computer, but I bet you won't get round to looking at them. Whereas, what could be simpler or more absorbing than flicking through one of your old notebooks and seeing a ragbag of information?
Computers are wonderful tools and incredibly useful. But writing is an imaginative act, so don't get sucked into using them for everything.