I moved your post to the Site Questions forum instead of the Shout Out forum, because you're posting a question, not a contest entry.
To log in, you can either go straight to the community (http://www.nextstepmag.com/community) and click on the Log In button, or you can go to our main website (http://www.nextstepmag.com) and click the Log In button there. You don't have to submit to enter the contest every time.
We're going to put a Log Out button directly in the community soon. For now, you can either close your internet browser (it will log you off automatically), or go to your backpack when you're logged in (click on the home/backpack link at the top of the page, next to the Next Step logo). There is a link toward the top of the screen in your backpack that should say "Not Alexis?" -- click that and it will log you off.