First off, this is not computer science
First of all, don’t sit there and say “I’m not a computer guy,” and dismiss this branch of forensics out-of-hand. It would probably shake you to your very core (well, maybe not to the core) to learn how few computer forensics examiners are classically trained — college degree in information technology, masters in computer science, etc. Remember that computers, until the last decade, were the kind of thing you learned on your own. People were hired on the strengths of their performance, and not on their degrees. The general IT job market bears this out as well — notice how many job postings for systems administrators jobs spell out the certifications they require, and not necessarily the degrees. Certifications were invented simply because so many computer folks learned in their basements, not at some fancy school.
If there’s one thing I have noticed over the years, it’s the number of computer forensics specialists who have no degree in computer science whatsoever. Again, this harkens back to the apprenticeship nature of the discipline — the guy or gal who happened to be pretty good with the computers at home, and honed that skill for forensic casework. So my point is that you should definitely not let the lack of formal training stand in your way.
If you’re totally new to the field, consider starting with Computer Forensics For Dummies. It will give you a great primer on the field, a general look at the software out there and the techniques that examiners use, and the type of work that examiners do. With this background under your belt, you’ll be situated perfectly to look at the specific software that examiners use (more below on this).
Of all the fields in forensics science, I believe computer forensics is one of the easiest to get into from the ground floor. Why? Because you can go to Amazon.com and buy a good certification book, study it, pass the test, and get a job. It’s plain as that. On job postings that do require a college degree, most do not require it be in computer science. The gotcha, though, is that you need to be certified.