Ultimately, you are trying to run a play in which the characters write their own script. You create the world and challenges for them to interact with during the play. Typically your players are the protagonists regardless of their actual moral outlook or actions. As the GM or the Director, you need to make sure they bear the consequences and the world responses to their input.
Many of the starting books come with everything you need to run many plays or "adventures" but eventually the players read the books from page 1 to page n or they can run a search utility on the reader to find the topic or concept being explored in the game. As a GM, this is a disaster because you need to challenge them and make them think. Its fun to sweat it out.
How do you keep ahead with a limited amount of time? You buy source books. Source books have new plots, new places to play, new villains, and heros. For the measly low cost of <$50, you get a pregenerated bag of new plots and challenges. My time is valuable and sometimes I don't enjoy fully fleshing out an entire alternate universe. There are people out there working for very small commissions working full-time plus to save us slags days and days of work generating this stuff. If you got the cash or gold pieces, throw them down and save yourself some time.
My questions to the group:
- What is your favorite source books? Please full cite your source so people can run out and buy it.
- What source book would you like to be created?
- Are there cute gamer chicks with red hair and freckles who are free and over 18?