Bob Carpenter has blogged about a new Intro to IR book online here. I'm looking forward to skimming it this weekend. I would also recommend the Python based NLTK Toolkit.
Books and resources like these are generally geared towards people with existing programming background. If a linguist with no programming skills is interested in learning some computational linguistics, Mike Hammond has written a couple of novice's intro books called Programming For Linguists. A novice would be wise to start with Hammond's books, move to the NLTK tutorials, then move on to a more serious book like Manning et al.
And if you're at all curious about what a linguist might DO once she has worked through all that wonderful material, you might could go to my own most wonderful List of Companies That Hire Computational Linguists page here.
And if you're not challenged by any of that above, I dare you to read Bob's Type-Logical Semantics. Go on, you think yer all smart and such. I dare ya! I read it the summer of 1999 with a semanticist, a logician, and a computer scientist and it made all of our heads hurt. I still have Chapter 10 nightmares.