411 REFERENCE · Wikibooks
Web Application Security Guide/Further reading
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
A similar guide can be found at https://wiki.mozilla.org/WebAppSec/Secure_Coding_Guidelines.
OWASP provides good information about many web application security issues, with a large list of vulnerabilities to learn about and avoid.