Table of contents
Where to start?
Founding an airline
Selecting aircraft
Cabins / service profiles
Traffic rights?
Flight planning
Maintenance
Stock exchange / AGEX
Operations
ORS
Personell
Accounting
Statistics
Competition
Glossary
As there are quite a few good articles already, I won't explain much myself. Follow the links and read those, they will explain it quite well.
Traffic rights are the legal framework that allows airlines to offer flights between different countries. As an airline, you can't just fly where ever you want.
Here are a few rules. In general, an airline from a given country can fly anywhere within that country. And additionally, it can fly from its home country to any other country in the world.
According to ICAO, there are a total of nine freedoms of the air. Wikipedia also explains these quite nicely.
Cargo is not affected by traffic rights limitations. In the game, you can fly cargo anywhere you want.
To further complicate things, there are some country pairs that you cannot fly (like Israel to Arabian countries).
As with many aspects, there are some simplifications in the game. While it is possible for airlines to fly from another European country to outside of the EU, these are governed by bilateral agreements. These are not covered in the game, for simplicity as well as reasons to not give EU airlines more advantages than they already have.
There is number of countries that allow you to setup a subsidiary and get full traffic rights in that country. These countries used to be mostly smaller countries that are not so attractive for players. The list includes some interesting countries thought that do allow for quite nice airlines (Ukraine, Kazhakstan, etc.). With the introduction of Hoover, the list has changed and is now much more restrictive.
On older worlds, these are the countries to let you outgrow your home market:
Newer game worlds starting with Hoover have a new, much more restrictive list. That is what is left on those worlds: