Communicating information from the GM to the players is usually done mostly verbally. The major exception is probably maps, which the GM can lay out or present piecemeal as the players explore. But don't overlook the power of illustration. Even if you can't draw very well, you can make a rough sketch to get across the layout of a scene or the weird sigils engraved on the cover of the evil wizard's book. Always have scrap paper and some pencils handy, and don't hesitate to scrawl something down when players ask what something looks like.

If they find a staff, hand them a piece of paper showing a quick sketch of a knotty, gnarled piece of wood with a strange knob on the end and some runes carved into it. If they find a potion, hand them a sketch of a glass vial with an odd shape and sealed with a blob of wax.

It can add a lot to the atmosphere of the game. And if you spring this sort of thing on them all of a sudden, also to player paranoia.

Transcript

Leia: General, evacuation status?
General Rieekan: Almost complete. Just the command centre and a few laggers to go. Then we can pull out the ground troops.
C-3PO: I hate to say it, but good work, General.
General Rieekan: We had plenty of time thanks to those ridiculous, lumbering camel droids. What a joke.
Leia: Captain, how's the ground battle going?
Captain Pharl McQuarrie: Here's a quick sketch I did.
Leia: Wow, they really do look like camels.
Leia: All remaining personnel to Bay F! Final transports departing in twelve minutes.
{cut to Han and Chewie still fixing the Falcon in the hangar}
Leia: {over PA} Repeat: All remaining personnel to Bay F! Final transports departing in twelve minutes.
Han: Are we ready to go yet? How many different things can possibly be wrong with a simple spaceship?
Han: Remember the Manka Hunter? It only broke down after we ram-raided Koda Station.
Chewbacca: Almost there, old chap. Just need a brief interlude lacking interruption from vociferous irritants.
Han: Why didn't you say? I'll go tell that loudmouth Princess to shut up.
Chewbacca: That... will do nicely, thank you.