I agree with Andreas that going out and spending a bundle on books may not be the best advice for a
new collector, who might be better served purchasing coins and then finding the information and
attribution he/she needs online.
However, from my perspective, I'm a book collector (read them, not just collect them). I'm fascinated with
history and the stories behind the coins. I'm even more intrigued by the studies that the coins I purchase provoke than the coins themselves. The internet can only give you so much. Many people would be surprised to hear that. There are
still pieces of information contained in the printed page than cannot be
had online.
On the other hand, not everyone needs to invest in something like the
RIC, though I admit I have, and use it often, as well as David Atheron who mentioned it above. I'd dare say that few collectors have this resource (even one volume, much less the whole set). "Think of all the coins you could purchase." as someone said.
The question remains then... How serious of a student of
history and
numismatics are you? Only you as a collector can answer whether or not you "need" to purchase the book before the coin. As your interest grows, so should your
library.