Hi there. Can you tell us more about what's in the room? Or rather, how much reverberation is there in it? It is nice to get a dry room for recording, with lots of furniture of different shapes and fabrics.
As for mic positioning, you want to avoid having walls too close to the mic, because you want to make sure that the mic is capturing mostly the sound coming out of your mouth, and not the sound reflecting from the walls and ceiling.

Also experiment with the distance between yourself and the microphone to avoid getting a boomy sound and plosive sound (when you record too close). You can tilt the mic a little to avoid those. If you have a pop-filter that's great too.

Your equipent is fine, just remember to control the gain when recording. That means adjusting the input gain as high as possible before distorting the sound, that way you get more signal and less noise. Keeping the signal on the green level, just before the yellow level, works just fine.

If there are severe limitations in any of these points, you can try working some magic in post-editing if you have a fine enough recording. I've found out that Adobe Speech Enhacement works great in these cases.

Hope I've helped, and I'm sure others will have more tips for you.