I would do it like this:
1. Level to 85, professions: Herbalism and Mining for lots of gold (for buying bind on equips at max level).
2. Get into normal 5 mans and 5 man heroics.
3. Get into the ZA/ZG 5 mans and do Baradin Hold weekly.
4. Get into BWD/BoT/To4W PuGs (raids), maybe you can find a sympathetic Firelands raid looking for a warm body to make up the numbers.
5. When 4.3 drops get into the new 5 mans.
6. Use the Raid Finder to get into the Dragon Soul raid and get into Firelands PuGs to fill out missing slots.
7. Get Deathwing dead.