1) What exactly is a "faucet" site?
A waste of time.
It is a website that is run by someone that has a source of income that pays them for getting people to interact with the website. Most often the person running the website is paid by advertisers for getting people to view the advertisements. The operator of the website tricks people into visiting the website (so that he can earn income from the advertisers) by paying the visitors extremely small amounts of bitcoins. The amount given to the website visitors is so small that it is generally unspendable. Since the transaction fees that you pay when you send a bitcoin transaction are based on the size (in bytes) of the transaction, and the size of the transaction depends largely on the number of transactions you received to create the funding, "faucet users" often find when they later try to send a transaction that the necessary fees exceeds the amount that they have available to send.
2) What is a "signature campaign"? I've seen those mentioned here as ways of earning bitcoins, and I've seen campaign pages, but nothing really explaining what they are are what to do with them.
A way for an advertiser to create an incentive for greedy people to fill the forum with thousands of posts of completely useless nonsense. The advertiser offers a small payment in exchange for the user to add the advertiser's ad to the user's signature space. The user is required to create a particular number of posts on the forum so that the advertiser feels that the ad will get noticed. Since the average greedy unknowledgeable user doesn't have enough useful and well thought out things to say to meet the advertiser's quota, they end up just spamming threads all over the forum with useless drivel. Serveral of the regular forum users have taken to blocking (using the "ignore" link) all users with a signature ad campaign in their signature. Therefore, by participating in such a campaign, you significantly increase the likelihood that helpful and knowledgeable users will never see anything that you post here.
3) Is mining worth the trouble/expense? I have read that solo mining is a waste of time, and that pool mining is the only way to be "successful," but for pool mining, does one need to invest in high dollar mining equipment?
Mining can still be profitable if you have access to inexpensive resources. If you can find a source to get your mining equipment inexpensively enough, and if you have access to inexpensive electricity, then it is still possible to be "successful" with mining. You should make sure that you have a good understanding of how to calculate how much bitcoins a particular piece of mining equipment is likely to generate, and how much the resulting electrical usage is likely to cost. You should then compare those costs to what it would cost you to simply purchase the same amount of bitcoins directly. You can then make the comparison and determine if you are likely to get more bitcoins for the same money by mining them or buying them.
Is there any use at all for the little USB ASIC(?) miners?
They are ok if you are willing to mine at a loss. In other words, if you interested in the mining process and aren't interested in being profitable but rather are just mining as an inexpensive hobby.
I guess that's good for starters
Thanks!
You're welcome.