Good start, Tom and Beth. One thing you'll want to consider is that just about any mount can keep the short 200mm focal length of your lens tracking accurately for at least a minute and probably several minutes. As such, you may want to try increasing your sub length to a minute or so.
Also, the only value to capturing multiple length subs is if you're going to do an HDR combination (where you use layers and masks to combine the different length subs). This isn't something you're likely to do at this stage of your learning curve. In fact, if you simply stack a bunch of 1/2 second subs with a bunch of 30 second subs without any adjustment (i.e., even weight), you'll have an image that is significantly worse than if you just stacked the 30 second subs alone.
So, make things simple for yourself and concentrate on capturing a bunch of subs of the same length (and skip the 1/2, 5, 15, etc. lengths). Then, take 20 to 30 darks (its only going to take you 20 to 30 minutes), another 20 to 30 bias frames (that'll take about 2 minutes), and (ideally), about 20 to 30 flats (skip this for now if the process might be a bit overwhelming - your lens has pretty tolerable vignetting at f/2.8, and hopefully you won't have any enormous dust motes).
Next, spend a great deal of time with DSS (or some other app designed to calibrate, align, and stack your images), and figure out how to properly make a good combined image. At this point, you'll be ready to start tackling the next monster - the processing beast.
When you're ready to for that part of the learning curve, I recommend you join the DSLR Astro Image Processing Yahoo Group
. Then, go to the Files section
and look for the file entitled "Challenge Links". In that file, there's links to several walkthrough videos (look for the URLs to the "walkthroughs"). They're each about 1/2 hour, and Neil does a great job of showing his excellent and straightforward workflow for doing this. Its a great place for beginning processors to learn a lot very quickly.
Also, you can produce nice images with Jpegs, but you're going to hit a processing wall fairly quickly. You're going to be disappointed with raws when you first look at them out of the camera because they'll be very dark. But, you'll quickly be able to learn how to stretch the images easily in Photoshop and start pumping out some top notch images.
Good luck with the adventure....