Sometimes using the "back" arrow on your browser will take you back to what you've been working on. Doesn't always work, but sometimes it does.

When you log into the site, right beside where you input your username and password, is a little box you can tick that says "Keep me logged in". If you click on that when you log in, you won't have that problem of being logged out of the site if you linger too long in one place.