First off, go for it.
However.....
You're missing a few fundamentals of mixing and of audio-for-film that are likely going to slow you down when you approach surround/multi-channel audio.
I can suggest a few resources for you to get started learning about surround.
1. Digi
Digidesign produced the book Pro Tools Sync and Surround Concepts a few years back that give a very basic introduction to some of the main concepts you'll need to grasp. It includes basics like terminology (for example, what the ".1" actually means in a format like 5.1). You can download it for free from the Support and Downloads / Technical Documents section of the Digi site. If luck is with me, that page can be found here:
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http://www.digidesign.com/index.cfm?...&itemid=23332>
2. Dolby
The Dolby website has loads and loads of info available for download (also for free). I'd suggest starting with the simpler Digi book, above, so you can be equipped to get the most out of the Dolby material.
3. Books
I got a lot out of the book "5urroundSound;Up and Running" by T. Holman. I see there's a second edition now available (try Amazon for more info, I know they carry it). The Dobly docs and Holhman book were how I got over the initial learning curve about surround.
Audio for Film
One more thing: Your original post also touched on some fundamental aspects of audio-for-film (things like track layouts, stems, etc.). Before you worry too much about 5.1 or 7.1 film sound, you'd do yourself a good service by soaking up a bit of the basics. One highly recommended book is "Sound for Film and Television", also by Mr. Holman.
I hope this helps and encourages you to keep at it until you achieve what you want. Keep us posted how it goes.
m