Your profile is the place where you can tell others users about yourself, what you work on, and put a picture of yourself for others to see.
Your profile has three items within the Actions menu:
Edit profile - Edit the details shown in the your profile:
Profile & Signatures - A difference on site from the old forums is that singatures are dynamic.The example below shows my profile displaying:
Change photo & avatar - Coming soon...
Edit Preferences - See Forum Tip - Turn of email notifications for details.