In film-world editing is known as "the invisible art" - and it's probably the hardest to teach. After the director, the editor is the next most important person on the production side of making films. Once the film has been shot the editor gets to work and the process of shaping and creating a story out of a film's thousands of miles of footage can take months - and sometimes years!
Most of the terms you need to understand for editing in TV drama can be found in the link below.
This link has most of the BASIC information on editing you need to know.
For practice in seeing how editing works in TV drama we can view a few sequences to identify the main types of edits and how they create meaning and narrative in a sequence from a TV drama.
Meanwhile, have a look at these abridged Youtube sections from "The Cutting Edge: the magic of movie editing". This is a "must see" for understanding the "invisible art". In Hollywood "the more invisible the cuts the better the editor".
Part 2 (Really useful for knowing about close-ups, flash-backs, parallel action, continuity editing, and editing for creating the illusion of reality, etc.)
For more from this film on editing you will need to buy the DVD with the same title.