I'm of the EXACT opposite opinion, having learned to draw in pixels before properly learning to draw at normal resolutions.
It is VERY important to get the base knowledge for how to draw down before you start going for specific stylization, as I've learned. The more aware you are of anatomy, the better you're able to succeed when you reduce and exaggerate it like cartoonistry and pixel art requires.
I highly recommend starting with the Andrew Loomis guides, Fun with a Pencil is an excellent starting point. If you google him, you'll probably find resources from him pretty fast.
I also recommend doing figure/gesture drawing, which is a practice technique that forces you to get fast and loose with your poses so everything is more fluid and dynamic. It's a great starting point for art practice, and there's several websites devoted to the practice, like my personal choise Quickposes.com which describes the reasons for doing it and HOW to do it better than I can here:
http://www.quickposes.com/tutorials Good luck, and stay on it! It's a long process, but not nearly as intimidating as that time investment or all the complaining us artist types would have you believe with the internet at our disposals.