I just noticed a post on bugtraq that states the Open Web Application Security Project (OWASP) has released a paper on building secure web applications and web services. From the post:
We are pleased to announce that the first release of the Open Web Application Security Project “Guide to Building Secure Web Applications” is now online in both pdf (1.67Mb) and HTML.
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The Guide covers various web application security topics from architecture to preventing attack specifics like cross site scripting, cookie poisoning and SQL injection.
At over 80 pages the guide is definately not a short read, but does look to be very comprehensive and of far higher quality than your average security paper. It's released under the GNU documentation license and is available via the OWASP website.
OWASP also has several other projects underway including an 'open source web application scanner called WebScarab (due end of the year), a set of generic API’s called Filters to allow developers to easily protect their applications from malicious input / output such as XSS (due in next 3 months) and a formal testing methodology.'