FAQ:

General questions
Prices and Values
Selling your coins
Supplies and Storage
Identifying a coin
For further info...

I just got some coins from a grandparent (or the coffee tin on the top shelf, or an old box in the basement..). What do I do with them?
Why collect coins?
What type of coins should I collect?
Where do I look for coins?
How do I or should I buy coins off Ebay?
I'm going to a coin show for the first time. What should I do?
Which side is the front and which side is the back? What do "obverse" and "reverse" mean?
Should I clean my coins?

Please keep in mind that I am not an appraiser, nor am I a dealer! I have no idea of precise current market values for most coins! Look at the first question to find out how to find the answers:

How much is this coin worth?
I have what looks like a silver US penny. Is it valuable?
I have what looks like a silver US penny, but it is not from 1943. What is it, and is it valuable?
I have a US quarter with a drummer boy on the back. Is it valuable?
I have a Lincoln penny with wheat on the back. Is it valuable?
Where should I go to have a collection appraised?

Where should I go to sell my coins?

What do I need to collect coins?
How should I store my coins?

What is this coin?

I'm no expert so I frankly admit I won't have all the answers. Here are some resources for finding the answers that I can't provide:

Usenet:

One of the best sources of information is the Usenet group rec.collecting.coins. If you've never read a Usenet group before, it's very similar to a cork bulletin board where people post messages and replies. There are hundreds, if not thousands, of subscribers worldwide to this newsgroup; many of them are renowned experts in the field.

You can read the newsgroup either through a newsreader (many web browsers come with them now) or you can subscribe to a service online that will allow you to read and post. There are many such services, but I generally recommend Google Groups. After you subscribe for a free DejaNews account, you can read and post to the newsgroup.

When you post, make your postings as informative as possible- the more information you give, the more likely it is that you will get a precise, accurate answer. Do not post images. It is a text-only newsgroup. Images bog down the loading time, and there are subscribers who pay per minute of loading time.

Check back each day for about a week to see if anyone responds, or just skim the newsgroup daily to pick up some new information.

Clubs:

Joining a local coin club is also a good way of finding information and meeting other collectors. For American residents, there is also the American Numismatic Association. They're a non-profit organization that offers many services to all ages of collector, and publishes a newsletter with tips and information in it each month. For international collectors, try a search in one of the coin site directories listed on the links main menu to find clubs near you. For more information on clubs, see the article: "Join a Club".

Ask the Coin Doc:

Coinsite has a feature called "Ask the Coin Doc". You fill out a form to ask your question, and the responses are posted on a sort of bulletin board. He'll take questions on anything to do with coins or paper money.

Ask an Expert:

Heritage Rare Coins has a similar feature called "Ask an Expert". You can email in questions related to coins and collecting. They also have a very useful FAQ sheet- be sure to check that first to make sure your question hasn't already been answered before submitting it by email.

Other sources:

Finally, there are plenty of sites out there that have FAQ sheets and other helpful information. Here is just a sampling of what's available:

PCGS has a lingo section, grading, coin news, a price guide, and more.
Chuck D'Ambra's Coins has a very thorough FAQ sheet and a glossary.
ICG (Independent Coin Grading) Coin Club has directories of dealers, clubs, and links; a reference library, books, software, prices, upcoming events, message/chat, and more.
Numismatica is a springboard to many other sites- articles, stories, FAQs, reviews, references, trivia, tips, and more.
One Minute Coin Expert is basically a more in-depth FAQ sheet, taken from another of Scott A. Travers's books.

There are other more extensive directories of coin-related websites; I have them listed on the links main menu.