I would start by buying a
RedBook and the Krause Catalouge of World Coins. I love looking through my albums and folders of everything that I have, but I also have fun looking at things that I don't have.
The cheapest way to collect coins, in my opinion, is to make your family and your friends at work aware that coin collecting is your hobby. I think that everyone, whether they consider themselves a collector or not, has some type of jar, cup or drawer at home where they keep their unusual coins. I think that most people save them because they feel they're woth alot of money, but in actuality they're only worth a few cents.
Buy a binder and some 2x2's to display what you have, and before you know it your friends will show you what they have as well. After you inform them of their coin is worth, make them an offer for it. Double the offer if it's cheap enough, but just be fair to your friends.
When someone you know goes out of country on vacation, give the a $20.00 bill, and ask if they can bring you some coins or notes back.
Before you know it you've doubled or tripled your collection. But more importantly you'll be having fun in the process.
Also, if you're going through alot of change at work, you may want to go through the notes as well to look for star notes and those with low serial #'s.
Kinte