Sorry if this has already been posted, but I have received a few messages in the past week about where to find the latest prices on certain items and/or how to trade your hats/items/etc. Most of these sites are well known, but for those who haven't heard about them, this is for you.
Scrap.tf is a great site for quick access the basics. You can sell and/or buy keys, hats, earbuds, maxheads, bill's hats, paint, description tags, +more at the convenience of an automated trading bot. Most items are sold at market price, and it's easier since you don't have to deal with adding a trader and waiting for them to come online.
You may also add a scrap bot, which allows you to put any random weapons (class specific doesn't matter) and receive metal for it. Scrap bots also allow you to buy any weapon for a scrap, although different scrap bots hold different items. It's a great site, check it out.
Backpack.tf is another great site, but specifically for pricing. The search bar at the top is an easy way to receive quick prices on all items and hats. It will also display the price of other qualities, such as Strange or Vintage. If you click on the Trading drop down menu, you will find the latest prices to TF2 Unusuals, as well as access to the most popular TF2 Trading sites like TF2Outpost.
TF2 Raffle is a great way to give back to the community (and also receive if you're lucky!). Once you sign in, you can click on New Raffle, and raffle off anything in your backpack. People sometimes raffle off unusuals, so keep an eye for that!
For more information on unusual trading, that may go in a different thread. I've had a lot of experience with paypal transactions, scammers, how to find out if your unusual is duped, finding the fairest prices and many other tips for first time traders.
Hope this helps.