As I've been saying all week, mistakes will happen in knitting no matter your skill level or the difficulty of the pattern you're working. The Internet and other knitters are both great resources for helping to fix whatever problems you might be having, but I think it's great to have a reference book or two on your shelf or in your knitting bag to help you with basic and beyond repairs to your knitting and to provide tips that might help keep mistakes from happening in the future.
A couple of my favorite books in this genre are Knit Fix by Lisa Kartus and When Bad Things Happen to Good Knitters by Marion Edmonds and Ahza Moore. Knit Fix in particular is really detailed and wide-ranging, offering great tips on things like fixed miscrossed cables and incorrectly colored colorwork.
Vickie Howell's Knit Aid is another good guide on knitty problems and how to fix them, and KnitSpeak by Andrea Berman Price may help stop some mistakes before they start because it will help you understand all the abbreviations and lingo that are do prevalent in knitting patterns and instructions.
Finally, I want to mention Lily Chin's Knitting Tips and Tricks, which is just a brilliant book that will make you a smarter knitter. Part of it is about mistakes -- I'm still blown away by all the ways she's come up with to use duplicate stitch to cover mistakes -- but the rest is just clever stuff you'll want to know and try in your own projects.
Do you have a go-to guide for fixing or preventing mistakes in your knitting? I'd love to hear about it!