Turning down the gain or using EQ in post to cut of the low end noise should help
In your audio editing program there's an effect you can to the audio track. The EQ is what you use to shape the sound. Most static sits in the low end so you can adjust it to cut out the low end, what audio program are you using? Also, if you turn down the gain on the mic and then double the audio in editing, it'll make it louder without adding in unwanted noise. That's how I do audio in our videos
Ummm, depends on how you are monitoring the audio. If you have audacity up while recording, make sure you aren't clipping the audio and before you start so talk as loud as you're going too and see if it clips and then be quiet and see if there's a visual hum on the audio track.
