Neonchameleon
Legend
Lots of good general advice above. So I'm going to go for three 4e specific pieces of advice.
1: Encounter/Short Rest/Daily. Bad names for what they are. When plotting and running, think of an encounter as a scene, a short rest as a scene change, and daily as an episode.
2: Fight Scenes. Fight scenes are a centrepiece of 4e. Make sure they aren't static line-fights with the two sides lining up to play patty-cake until one drops. To help, always put in at least one interactive piece of scenery (even if only a window to throw people out of or a camp fire to throw them in). Also make the spaces fairly large. And don't run more types of monster than you can cope with.
3: Skill Challenges are your friend - but don't let them near the players. What they are good for is dealing with improvised plans. In almost any other game system I know, until you get the hang of it you need to work out what each skill check as part of a plan should be. In 4e you just find a level for the plan, guess at the complexity (possibly modifying as the plan goes further off the rails), and mark off a tally chart of each success and failure. DCs are done for you - easy, medium, and hard depending what they are trying. Just don't let the PCs play mechanically to the skill challenge - they are simply a tool for you to very easily handle the mechanics and keep score so you can focus on the interaction or narrative.
1: Encounter/Short Rest/Daily. Bad names for what they are. When plotting and running, think of an encounter as a scene, a short rest as a scene change, and daily as an episode.
2: Fight Scenes. Fight scenes are a centrepiece of 4e. Make sure they aren't static line-fights with the two sides lining up to play patty-cake until one drops. To help, always put in at least one interactive piece of scenery (even if only a window to throw people out of or a camp fire to throw them in). Also make the spaces fairly large. And don't run more types of monster than you can cope with.
3: Skill Challenges are your friend - but don't let them near the players. What they are good for is dealing with improvised plans. In almost any other game system I know, until you get the hang of it you need to work out what each skill check as part of a plan should be. In 4e you just find a level for the plan, guess at the complexity (possibly modifying as the plan goes further off the rails), and mark off a tally chart of each success and failure. DCs are done for you - easy, medium, and hard depending what they are trying. Just don't let the PCs play mechanically to the skill challenge - they are simply a tool for you to very easily handle the mechanics and keep score so you can focus on the interaction or narrative.