Wow Loughton into the city is not going to be a fun daily commute - if that is what you will be doing. I don't have any experience taking the Central line out that way, but I lived in a couple different places in Hertfordshire while in the
UK and being on the Met line for 45 mins to get into the city was unfun. Use to take the Northern line - Edgware branch as well, which wasn't quite so bad.
Do you have friends or extended family out in Essex? What part of London do you need to commute to? That's a lot of track to be going up and down on a daily basis and the more of it you're on the greater the chances are of getting caught up in delays or one type or another.
One thing you will pick up on after you've been using it a while, is which lines to use and which stations to get off at to get from a to b to c the easiest. I'm not sure where you are coming from, but if you've spent time on subway systems before you'll have no problem.
Regardless, the tfl site will handle all your travelling needs.