There are different pools for each altcoin, though some pools switch between different currencies, based on rising and falling values. There are pros and cons to each pool, but for the most part it won't matter which one you choose. To find a popular pool, visit a community site for the coin you're interested in mining--Reddit has active communities for all of the popular altcoins, for instance.
We chose the WeMineLTC pool, which is very popular. There's some concern in the Litecoin community that WeMineLTC is too popular, because if more than half of the total mining of a coin is being done by a single pool, the currency isn't secure. Since it's unlikely we'll be contributing much mining power, that's not a concern for us.
The second major decision you'll need to make is whether your want to use a CPU miner or a GPU miner. These are different forms of the mining software designed to utilize either your PC's computer processor or its graphics processor.
GPU miners are much more efficient, but only if you have a discrete graphics card. AMD cards are much more efficient at altcoin mining than Nvidia's, so much so that the street prices of Radeon cards have skyrocketed in past months.
If you'd like to mine on a laptop or low-end desktop with integrated graphics, you're better off using the CPU miner. We'll show you how to use either one. You can even mine both ways at the same time, if you want to really get all the mining power you can out of your computer. Just watch that heat and power usage! A diagnostic tool like CPUID's HWMonitor can help you keep tabs.
To mine with your computer's GPU, you'll need a piece of software called cgminer. You can download a Windows executable at http://k-dev.net/cgminer/. You specifically want version 3.7.2 of cgminer, because later versions removed support for the scrypt hash function used by altcoins. (GUIMiner-scrypt is an alternative that also supports altcoin mining and uses a graphical interface, rather than the command line.) In our tests, Chrome said the cgminer software was malicious and blocked the download, but it's not; you can either disable Chrome's malware protection or use an alternative browser to download the program.
You don't need to install cgminer; just extract the contents of the zip file to a location on your hard drive. Cgminer works from the command line, but you can also run it using a batch file. If you're not familiar, a batch file is basically just a saved command prompt script, and you can write it in notepad. Before you do, you'll need to get a few pieces of information from your pool service. You'll need to know the following for your batch file: