Where to buy RAM for iBook?

Try http://www.crucial.com or http://www.macsales.com

Both are very reliable and offer good prices. Don't buy very cheap RAM, it often leads to problems down the road.

I have to disagree. 99.9% of the time, ram either works, or it doesn't, and it's like that way forever. I have never seen a case where ram fails part of the way into its lifespan. Cheap ram may be a little more likely to be defective, but they replace it for you anyway. Crucial, and other "brand name" companies charge a premium for peace of mind. The ram almost always works the first time, but, in my dealings with many other companies, so do theirs. Kingston is the only company that I consistently get bad ram from. All ram comes with a warranty. You will very seldom need a lifetime warranty, and ram manufacturers know this. Where ram breaks down, it is predominantly due to some external action, such as discharging static, or physical damage to the chip. Just walk into your local computer shop and pick up a stick of PC2100 SODIMM. Mac ram is the same as PC ram, and has been for many years. Don't worry about brand names, as you will hardly derive a noticeable benefit.

Well TLRedhawke, I think you agreed with me more than you disagreed. I was trying to say the same thing in one sentence and I guess my choice of words wasn't very good. I didn't mean that the RAM will work for months and then just stop working. But, we all have read posts where a machine will work for a day or two and then magically start with kernel panics and instability. And guess what? The owner recently installed some new RAM.

Point is that there are plenty of good dealers offering reliable RAM at good prices. The OP stated that he is new to the US so I just didn't want him to hop on eBay where he probably won't have a warranty or support.

I stick by my recommendations of crucial and OWC. I've never heard a bad word about either. And yes you are paying a bit more for peace of mind, but isn't that also why we all bought Macs? You get what you pay for.