Debian maintenance question: apt-get vs. dselect vs. dpkg-- help!

[wells]

So I have been running Debian for a month now after jumping ship from Red 
Hat and I'm trying to devise a solid method of maintaining my system.

What's the best way of installing things? Apt-get? Dselect? Compiling from 
source?

Moreover, what's the difference? I see apt-get, dselect, dpkg-- what do 
these do and how are they different?

Opinions, thoughts, insights, methodologies appreciated.