Background:
I recently graduated with a masters in computer science but my studies didn't include any web programming. I have a full time job as a Java developer but I'm looking to start a side project, a gaming website similar to IGN or many others, but with the goal of making it better for the users. There's an argument on whether that's possible, especially as a beginner, but that's not what I'm looking to discuss right now.

Details:
So the site will be primarily a news site, with articles users can comment on. There will also be a forum, which I want integrated with the site, not separate like so many others (one login, one profile, one set of stats). Beyond that, future content will be user achievements, youtube videos, podcasts, and a specialized form of tagging to allow for content to be separated into "subsites" which only feature relative articles, posts, etc.

I taught myself HTML, CSS, and some Javascript as well as the basics of a few other languages. I also have previous (beginner/intermediate) knowledge of Python. I have Apache and MySQL installed on Windows (but I have nothing against using a Unix system instead).

Looking for recommendations on:

*Server-side languages and frameworks (Looking at PHP or Ruby on Rails for now)

*Web hosts

*Pre-built vs. custom code for features such as forums (Leaning toward custom or at least open source)

*Any other information you can give- this is the only place so far that I've asked for input, beyond a few of my friends who have pretty biased or unknowledgeable answers

My main concern is that I get this started right so that down the road, I don't have to overhaul the site or make big changes that would be visible to my users, as that's the biggest pain in this industry, consumer-side.

Also, I'm aware there are other threads on these topics and I will be reading through them, I just wanted to get this post out first so I could hear from people individually and get some discussion going.

Thank you!