So I hear a lot of talk about "pushing" things with adb shell, and from what I've read I believe this requires a PC? If I have a Mac, and want to perform some of these actions, can they be done with the terminal emulator, and if so, do I just copy exactly the directions for adb or do I have to change them slightly? And yes, that was quite the run-on sentence, my English teachers would probably cringe...
cmotion,
The Android SDK is also available for the Mac (and Linux). In fact, from what folks have posted, hooking your phone up to your Mac doesn't result in the USB connectivity problems that a lot of folks have on their Windows-based PCs.
You can't use adb from the Terminal Emulator since its a client-server pair: the adb.exe on your PC (or Mac) communicates with the adbd daemon on the Android-side (your phone). So, you can't really do the phone-to-phone thing via adb.
Instead, you would just use the Unix shell commands from the Terminal Emulator to copy things to and from your /sdcard (if that's where you were going). For example, let's assume you've started-up the Android Terminal Emulator and you want to
copy a ROM from your /sdcard/download directory to the top-level of the /sdcard, you would type:
cp -p /sdcard/download/your-rom-name.zip /sdcard/your-rom-name.zip
- or a slightly less verbose version to accomplish the same thing:
cp -p /sdcard/download/your-rom-name.zip /sdcard/.
-- or , you could
move it instead of copying it --
mv -i /sdcard/download/your-rom-name.zip /sdcard/your-rom-name.zip
-- and the less-verbose version (you can see where this is going) --
mv -i /sdcard/download/your-rom-name.zip /sdcard/.
The world is your oyster with Unix and a shell prompt

.
If you really just need to transfer files from your Mac, you can just install the SDK (
Android SDK | Android Developers) and use adb push and pull like you've read. Or, you can just hook your phone up as a disk drive and transfer files with your favorite file explorer.
Cheers!