Based on what I have read, it seems that the secondary fermenter is considered an intermediate level and optional prodedure. You'll notice a lot of stores that sell glass carboy's for secondary fermentation in their 'intermediate' kit. I have bought all my equipment, but I havn't brewed my first batch yet, but when I do brew my first one in a few weeks, I plan to use a secondary fermenter. I think a lot of "beginners" start out using secondary fermenters as well, it is really a simple prodedure, its as simple as just racking to another fermenter, and waiting, thats it, just have to be careful and make sure you sanitize everything and try to avoid oxidizing the beer.
You can definately brew beer with a single fermenter though, I think the standard time in a single fermenter is 2 weeks then bottle. After one or two batches you might decide you want to go with a secondary fermentation. To upgrade your kit all you will need to buy is a glass carboy, a drilled stopper, and if you want a secondary airlock. The extra airlock would be optional since you could just transfer the airlock from the primary when you move to the carboy, but I suggest buying another one. It is always good to have an extra plus they are less than a dollar.
Either way I think you will be pleased with the results. Let us know how things come out.