Encounter help and campaign ideas
Encounter help
Go to Sally Beauty Supply or some such place. Buy a bag of tiny multi-colored rubber bands. Cost: $.69 for 250-odd markers of various colors that you can hang or lay on any mini/counter imaginable. Separate into zip-locks and give to the person that has the most organized mind. An engineer of some sort if possible.

It is now there responsibility to help keep track of status effects. These include: Slow, Prone, On-Going Damage, Marked, Shrouded, Bloodied, etc..
Get a small white erase board and some dry erase markers. Do not confuse these with the wet erase markers you use with your battle mat (eek, permanent maps). Give the white erase board to the person that likes to be in charge. They now keep track of initiative.
Give a small pad of paper to the person that likes to argue the most about rules. They now are responsible for noting any rule questions that come up during play that you don't want to research right there on the spot. It's up to you to resolve the rule quest after the session but before the next one.
Campaign Ideas
Don't plan a campaign right now. The best way is to see what pops into your head during the first few sessions. Also, see what your players do and say. They will come to some of the damnedest conclusions possible. Often wildly more creative than what you can come up with. When that happens, run with it.
Save your NPCs. Whenever possible have them reappear. Need a kidnap victim? Use a friendly NPC. Need another? Use the same one. One kidnapping is foul banditry. Two? That's a CONSPIRACY!
(Below is straight from Dresden Files campaign development)
Create locations, not worlds. Develop themes and threats for the town or region you adventure in. Themes are things that are just happening. Threats can be big, small, mysterious or simmering under the surface. 5-10 minutes per Threat/Theme. Maybe brainstorm a bunch and cut the list down to three or four favorites.
For each Threat or Theme you make some Faces (NPCs). Just a name and a sentence explaining their relationship to the theme/threat. Three Faces per threat/theme. This should take 1-2 minutes each Face.
Create specific locals (The Moon Market, The Rusty Kettle Inn, The Backroom at The Bakery). These are stand alone places that the story can take place. Give them a Face. 2-5 minutes per Location and Face.
Add some extra Faces. 1-2 minutes each.
So in the course of one hour you've created a place and populated with meaningful stuff/people/places. Now unleash your players in it. When they ask for a market, send em to Moon Market. A Inn? send em to Rusty Kettle. Looking for trouble? Let the rogue find the backroom gambling at the Bakery.
The "Big Picture" Stuff doesn't really matter until they get more important, IMO. If you like the idea of a nefarious bad guy

pulling the strings behind the entire campaign, be certain you don't blow his cover to early. If they must learn of it make it happen through Lieutenants or Foiled Plans.
Feel free to ask for refinements or specifics.
Edited to add this:
Step 1
If you like reading, check the story hour section of EnWorld. You fill find more awesome ideas for campaigns, encounters, traps, NPCs, backstories and shennanigans than you can shake a stick at.
Step 2
Steal all the good ideas
Some of my favorite threads:
Lessons From DMing with my GF
This one is insanely chalk full of some phenomenal GMing advice. Also he's a great writer. Don't let the thread title fool you. It's got lots of non Girlfriend specific advice. Zombie Apocalypses. Strange island worlds. Adventures and insights abound. I read this one straight through in 3 days. Beware.
One of PirateCat's Campaigns: Tons of 4e mechanics exploration and a great yarn as well. Also, PCat kinda runs this joint, with Rel and others (see below).
Rel's Campaign: I was blown away by Rel's adventure world. I've wanted to use it for months now. His approach to deities in his campaign was super cool, IMO. I stole that. Sorry.
The above are not strict story hours. They also explore the mechanics behind the encounters or ideas the GM was experimenting with. Solid Gold. BTW, The first one is not a 4e campaign but his lessons have nothing to do with rules. They are invaluable none-the-less.
Just remember to stop reading in time to plan your next session and/or go to work.