If you’re not sure what you should read next, read these articles.
“What Every Computer Scientist Should Know About Floating-Point Arithmetic” by David Goldberg
“The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets” by Joel Spolsky
“What Every Programmer Absolutely, Positively Needs To Know About Encodings And Character Sets To Work With Text” by David Zentgraf
“What Every Programmer Should Know About Memory” by Ulrich Drepper