For how, I wanted to give a shout out to some of my favorite nerd-rated websites. Please note, this is not a comprehensive list, some the ones coming to my currently very sleepy mind:
Want to know about newer games, when something was or will be released, or need a large and active message board community devoted to your favorite game? Chances are, GameFAQs is the place to go. They also have a comprehensive selection of of user-generated walkthroughs, tips an tricks, and more or less anything you could want. I also pop on their message boards related to Comics and Graphic Novels, Star Wars, and games I loved (wanted to love) and would like to see more done with (Brink). Sure, there's a lot of chattel on the message board, but they're usually good for some entertainment or interesting insights.
I'm sure I mentioned this website when I wrote about how to start collecting comics, but it is still incredibly useful. They have an extensive list of back issues, TPBs, and alternate covers. Also, they are priced appropriate based on condition, which is the one are Amazon can be a bitch sketchy about. Prices tend to be competitive with Amazon as well (it's the only other site I use to buy comics). The Wife demands I giver her credit for this find, because before she did the research and looked it up, I was generally forced to hunt on eBay...
This isn't exactly a nerd resource, but it can be instrumental in helping you do something like build a nerd-cave. Freecycle is a website where people sign up for groups broken down by town. On this list, they can post OFFERS of things they have at their house but don't want any longer, ranging from furniture to electronics to books, or post REQUESTS if they're hoping someone has something they're looking for. The trick is that everyone on this website is for free -- folks recycle their items here when they might otherwise thrown them in the trash. If you have a way to haul furniture around, there are some really great finds -- I've added a couch and bookshelves since moving back to MA, but many states and towns are represented.
I'm not much one for Social Media, but if you are a fan of something, try to look it up on Tumblr. You will find entire fandoms (groups dedicated to a particular show, series, movie, etc...) based around any given thing and can either join in the discussions or simply follow them and watch. I personally subscribe to these fandoms: Supernatural, Marvel, Cthulhu/Lovecraft, Harry Potter, and plenty more. Some of the posts are hilarious, more insightful, and some quite surprising. Nothing quite like a good Misha-pocalypse.
This is a YouTube channel I've mentioned before, but I strongly suggest you seem them out. My favorite shows on the channel are Wil Wheaton's TableTop and Felicia Day's Co-optitude, but there are many more that can appeal to any nerd.
That's about it for now. There are doubtless hundreds more and I skipped any of the myriad sites that deliver news. I'll add to this list periodically when things spring to mind, so please feel free to drop a line with your own suggestions!