I'm a musician/engineer and have not used pro tools in ten years, I'm now researching cheap ways to get up and running at home, and need advice on MP9 vs. Pro Tools SE, and how to get bang for my buck in the computer Department as well. I'm fairly well retarded with computers, and want to keep it simple and effective; a dedicated computer, only running pro tools. Any perspective would be greatly appreciated.
You'll have to figure out whether you're money rich or time rich. "fairly well retarded with computers" is basically an argument against being time rich. :) I'd say go with vanilla Pro Tools 9 or 10. It runs on any interface and you will end up with Pro Tools, not another half-baked DAW that never made it to industry standard (and by this I mean PT is the half-baked DAW that did). I'd say stay well away from Audacity, regardless of what the word is. The same with Reaper (and for this I expect to get flamed). The good news is PT costs much less these days.
I'm an avid Pro Tools user but haven't really compared those two options. I believe Pro Tools SE only comes with Avid/M-Audio bundled hardware so if you are getting those hardware, you can try it out first before knowing to buy M-Powered.
I'm not sure what else you are looking for with regards to advice so some specifics would be useful.
If you want cheap, you can try out Presonus' Studio One Free as an alternative.
If you're not too attached to ProTools, you could even look at free software like Audacity.
And if you want some tutorials to guide you through ProTools features and techniques, you might take a look at http://www.lynda.com/ . I believe they've got a bunch of videos there and I've heard good things.
There is a learning curve to any DAW, so regardless of how inadequate you feel towards computers, you will always have to learn the clicks and menus on all of them.
From being a user of a few DAWs (currently use PT), your workflow and understanding of any of them is relatively similar; the main goal is to gain those clicks and hand contorting keyboard short cuts. I would concentrate on getting a core DAW that is stable and has a good community for keeping you in the know and full of potential updates and plugins; I would recommend PT10 or Cubase.
Just be sure that you pick a DAW that you can afford.
Personally, I would recommend both Cubase and Pro Tools. Both have strengths, Pro tools is great for simple sound editing and Cubase holds the monopoly for Midi sequencing and in the box music creation.
Logic Pro is another good DAW if you are an apple user, but from the current trends from the apple pro developers, Logic could be up for a "dumbing" down in the next year or two. Great at the moment tho and very stable platform on Mac.
Unless you have a specific reason to use PT, consider (preferably try and see yourself) all alternatives, because they can feel subjectively better.
M-Audio, nor Avid hardware are not known to be very good bang for the buck (unless the hardware is required to run PT), so even here there are a lot of alternatives.
It's all just a matter of taste, but only you can decide what you want to use and how much you want to pay.