not just every "new" knitter, EVERY knitter has this happen -- it's just more common when you're first starting out and getting used to trying to hold all that stuff together that's sticking out in random directions. Plus as you gain experience, a needle falling out or a stitch dropping becomes less likely to trigger a DEFCON 1 alert.
The videos on the main KH site cover a wealth of topics, and one of them is how to fix a dropped stitch. If you're in even deeper trouble than that, she covers reinserting a needle that's fallen out completely too. There is actually a whole collection of videos on fixing mistakes if you scroll a little way down on the "Tips and Techniques" page. I usually fix mine with a crochet hook because... well, that's how I learned to do it and it's easier for me to work with a tool that's not already encumbered by stitches. But that's just me. YMMV.
The trickiest part is getting the stitches back on the needle without getting them twisted. when you're done, the side of the stitch facing you should look sort of like a backslash (). But it might be hard to see unless you pull the loops on either side out a little. In time you'll be able to feel the difference when you try to knit it if it's twisted.
To help avoid the problem in the first place, you might try bamboo needles. They're somewhat less prone to falling out than metal or plastic ones. They cost a little more, but they're not unreasonable. Using circular needles (which can be used to knit flat too) helps a lot of people keep from losing stitches this way too.
Hope that helps... and welcome to the dark side!