I have a good understanding of C, C++ and java. I have an idea about a web app (as a self learning project) but don’t know what technologies would be needed to create a web app. Also if possible include some resources that can help explain how these technologies are useful.
I am trying to implement a system where sellers can post whatever they want to sell and buyer can search for item they would like to buy ( like ebay.com or craigslist.org but with really basic functionality, I am just a beginner).
How small/big should it be? Do you need some kind of persistance? Should it be interactive?
Anyway, you’ll need some HTML, CSS and Javascript basics. But then, you can write useful web applications in java (see e.g. Google Web Toolkit or another ten java web frameworks).
Understanding HTTP helps a lot, also (if you have the time to read some background information on that matter, i recommend Fieldings PhD thesis on architectural styles for network applications)
In the end, it will all depend on your scope and your interest. There are other nice frameworks out there, built and refined especially for web applications like