The biggest issue with 4e is that the flow isn't very fast, especially with new players.
A few tips to help with that.
1. Make sure all players have complete power cards filled out. If they can use the Character Builder, then that is the best bet since everything is automatically filled in, including bonuses for each attack etc. Otherwise, just make sure they figure out and write down the stuff for each power someplace obvious.
2. Stipulate that damage dice are rolled with attack dice. Then a player can have the dice in hand when their turn comes around and if they hit, getting damage is as simple as looking at the other dice.
3. Assuming your encounters are all pre-planned, have a copy of each monsters stats, basic and special attacks on a separate card. Premade adventures normally have a nice thing you can print, or you can just copy the stats from the book. Have each player create the same type of card for their characters, including basic attack modifiers and total damage dice for their at-will, encounter and daily powers. Include a section for their initiative for the encounter.
Now, when an encounter starts, you can roll initiative, and write it on each card and order them in their turn order. As you are going through the turns, simply flip the cards and if it is a creatures turn, you have what they can do written right there and it is easy to resolve.If it is a players turn, you don't need to be questioning them about each power, since they will likely have powers that you won't recognize by name, but can look on the card real quick to remind you.
4. Have a turn time limit. If things are flowing smoothly, you don't need to enforce it, but having a minute hour glass that you can flip over for those turns that it seems like everyone has a crazy idea they want the person to attempt.
5. If a character will often be switching weapons have them have card with a weapon on both sides, so you know what they have and no one forgets during a long turn. As they switch weapons, they just need to flip the card over. The same for weapons that needs anything but a free action to load (like a crossbow takes a minor action), have them have a card with loaded or unloaded on either side, so they don't get confused and end up making an attack with a weapon that in unloaded, especially if they don't have an action left to load it.
6. Either have maps set up in advance, or have the peices to make the maps set aside to have it happen quickly. In my group, most of our encounters that are not directly in a dungeon, are done with a grid map on the bottom and a clear plastic map on top that has the area drawn on it with wet erase markers. I often thing that pre-drawing (or printing on a PC) would be better, with a grid directly on the clear plastic, then switching maps would be instant. edit: You can even use something like
MapTool to make a map and then print out to use without a plastic mat, but that requires a bit of time to get set up.
7. Have your figurines for encounters separate before hand. Digging through stuff in the middle of the session just slows things down