I have downloaded these files and attempted to solo mine from them but have yielded no results even with the smallest difficulty of the altcoins. Do I need to to join a pool mining group in order to yield results on a daily basis? Or is there more to it than just simply downloading and clicking solo mine?
If you want to see results from solo mining, follow the "Alternate cryptocurrencies" board for newly-released currencies. You'll have to catch them in their first few days (possibly hours) in order to see any results. Often you can catch them before pools exist, though if you're CPU mining you're still competing against the people with GPUs. Plus you'll probably either have to get their code to compile or run a Windows version of their client. By the time a coin gets enough attention that someone puts the work into making a Mac build.
That said, I believe you can run most of these clients as solo miners in server mode (is that what it's called? someone help me out here) but point a standalone mining app (capable of interfacing with your GPU) at them. You'll still be solo mining but running multiple apps.
That being said, don't get your hopes up if your Mac doesn't have an ATI card. The NVidia cards you can get with a Mac are great for processing graphics, not so great for mining coin. I can get 20MH/s out of my NVidia 8800GT on a good day mining SHA-256, and anyone here will tell you that ain't much. I haven't successfully gotten the NVidia to mine scrypt-based currencies faster that 2-3KH/s, which is slower than a single core of CPU mining.
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that being said, go for it! It's one of my pet peeves when people say not to bother if you don't have the "right" equipment. You'll learn a lot and hopefully have fun getting it working with whatever you've got to mine with, and if that doesn't discourage you, there's never anything stopping you from upgrading. When you upgrade, you'll 1) be up and running and only learning the ins and outs of the new device, not everything from scratch and 2) have been around the block long enough to make smarter choices about what to buy.
This morning I solo mined two blocks of Lebowskis. It's a joke coin that was launched yesterday but it was a very gratifying experience to be able to solo mine something on my CPU. The days of being able to actually find my very own blocks solo mining anything else are long past. (And yeah, I did it in a Windows virtual machine.)