I want to know when you guys launch your product, app or website what is the first thing you do in order to let people know about your product, or what websites you visit to create buzz about your product or venture?
You're doing it backwards (and I know some startups that have made this mistake). What you should look at doing is building a community/conversation (or even contributing to a separate community/group in which you know those people fit your target demographic) around your product before it's even ready.
The channels you use will be different for everyone. You'll want to focus on where your market is- where do they engage with each other? (For example, if you're confident your demographic doesn't use Snapchat then there is no reason to put effort into that platform).
Look to start building yourself now. Go to local meetups. Contribute to communities AS your brand. Gain recognition.
Now you're ready to sell to them.
I'm really getting to like William! This is the third time today I have agreed with him.
The first thing would be to let all the people who contributed to the development of your product know that it's finished (not that they shouldn't have known it was nearly so already).
Creating buzz is a PR job, but PR is ineffective if it's not relevant. So, exercise those relationships again that you built during development, the people who helped you test and modify your pilot, and make sure those pre-launch fans have an easy way to share the news, demo, sample, whatever is appropriate.
Read the Lean Startup.
As a PhD friend once said: 6 months in the field can save you 6 hours in the library ;-)