Almost every major industry has it's standard publications which are considered "must reads" in that particular field. After spending some time on Google looking for web application publications, I've come up empty; are there any high quality web application publications available online or through print that someone can point me to?
Good question; as one commenter pointed out, there are trade sites/magazines that focus on a technology, but like you I've not seen a publication that focuses just on web apps and their development.
Two publications that have a lot of web-dev-related content and may be of interest:
Hope that helps!
If you're talking .NET
These aren't specific to webapps, but often contain a large number of articles on development in the web space: