The first programming book I ever read was the most influential.

A picked up a copy of Algorithms + Data Structures = Programs(N.Wirth) from the college library when looking for ideas for a term project, probably because it was the first one on the shelf in the computing section.

Even though it didn't directly relate to the project I ended up doing, I extended the loan to the maximium period allowed, and then took a permanent lean on it(flag that meant whenever the book was returned a note was left in my pidgeon-hole), for the rest of that year and when I asked to do so the following year, they bought a second copy.

There is a deceptively simple idea in that title, that in 1976 way pre-dated the OO movement, but it encapsulates a great deal of mileage. All programs exists to manipulate data of one sort or another, and arranging that data into suitable structures to give the algorithms applied to it, easy, efficient and reliable access to those parts of it they need, is what that book is all about.

Shame it is out of print. I've already bought two copies. One I lent to a colleague who never returned it, the other I left at a customer's site somewhere in Germany when rushing to catch a plane and I never got back there. I've been waiting for a re-print to buy another, but it seems I might have to put up with a second-hand copy :(

This is a good read too, but you probably wouldn't spend money on it unless you're a Wirth fan.