Re: Essential skills for any software developer

[johnlawrence]

I find regular expressions are useful pretty much daily, and I'd certainly recommend Mastering Regular Expressions.

Other than that, a good understanding of any tools you use every day will make everything run smoother. I'd also suggest The Art of Computer Programming

As you mention the MIT opencourseware I'd also point out that other universities do similar see OCW Consortium and if you use iTunes, the iTunes store links to iTunesU which contains a lot of useful podcasts etc.