fender,
The 410 has built-in preamps, so that should get you started without the need for any external gear.
Essentially, the interface is just that - it interfaces between an audio signal and a data signal in order to get your wonderful music into the computer. The preamp is a device that boosts the signal of the microphone (or instrument or whatever) to a level where it can be heard. In the case of your 410, you have a combination interface and preamp (well, actually two preamps to be more specific).
At some point in the future, you might like to use a different preamp, which you can certainly do, but the 410 along with a decent microphone should get you started just fine.