I don't know enough about Reaper to comment - and, I'm a PC guy these days, running Samplitude Pro X Suite as my main production platform ( although I do have a version of PT for those clients who have recorded their tracks with PT and insist on keeping it in that format) so keep this in mind when reading the following...

Most pro guys I know who use Macs are using either PT or Logic, with Logic fast becoming the preferred platform. PT is the industry standard, and how it got that way has already been discussed here on many threads over the years, but Logic seems to be the up and comer. If you plan on doing this professionally at some point, strictly from an accepted industry standard point of view, you'll probably want to look at Avid... but I know more than a few Mac guys who have switched from PT to Logic because they like it better. I've been told, and have read, that PT has come out with new versions, where they brag about "new and innovative features" that Logic has already had in their platform for years.

It really all depends on what you want to do, what your workflow is, and of course, how much money you want to spend. While I have only a little experience with Reaper - occasionally using it at client's home studios - I don't see anything that is necessarily wrong with it. Any complaints I've heard have been mostly about particular features missing, that the more expensive programs have, but at that point you have to take into account the price difference between them.

As far as the preamp/i-o you are looking at, I've heard nothing but great things about it... although it lacks a midi interface, so if you are planning on doing anything with midi, and you don't currently have a midi interface, you'd need to get a standalone midi i/o, something like this:

http://www.sweetwater.com/store/detail/MIDISport2AE

FWIW

d.

Reaper is excellent value for money, but does have a fairly steep learning curve. Logic is the go-to DAW for Macs, but it comes at a price.

Given that your SD USB Pre 2 is only a 2-channel device, you could experiment with Audacity, which is free. It's pretty limited in terms of functionality, but it would get you started.

Thank you both for the recommendations. Logic seems like the logical, no pun intended ;), choice to go with, and the integration with the Mac computer is probably smooth as heck.
Good idea to try Audacity first. I'll probably try that first just to get my feet wet, and read about and get familiarized with Logic before going with that.

I'm not exactly sure what MIDI is. I've heard it used in sentences in, what seems to me, various contexts. When and why would I use MIDI or make MIDI tracks? Is it an alternative or addition to other methods of recording?

Cheers,
Aaron

Garage band is good to get you going. Then something like reaper or another daw that comes with an audio interface. The interface sends audio into and out of the computer.

MIDI is used to communicate between keyboards/drum machines/ect and a computer or other midi device. It send info like what nite you play, and for how long, how softly, ect. It's kinda like musical notation for machines.