Rather than just opening a laptop and just mucking about, it's often best to sit down and create a route that'll you'll actually use. This doesn't have to be some exotic three week tour of Italy and Spain, which bods sometimes start on five minutes before they depart and then panic when they can't crack it in 10 seconds, but a simple say morning or day ride around roads you are perhaps familiar with. Add in a couple of roads that you don't know so you well, too. That way you'll quickly learn how and why everything works. Not least, you'll learn how the route(s) you plot integrate with the GPS device.
None of it, whether it's Mapsource or BaseCamp, is the monster some people like to make it out to be. Trust me.
If you get stuck, the chances are you'll not be the first person to encounter the problem. Have a look here or just Google your question in a few words. Similarly, look at You Tube videos; some of them really are very good.
Whilst there is no definitive right and wrong way to do things, there are some very simple basics that near enough make life easier for everyone. You'll discover what these are as you go along. But remember, when all is said and done, it's all based on Personal (with a capital 'P') computing and on a Personal GPS device. If you are happy with your settings, route creation and ultimate useage one way and like the results it gives you, then do it that way.