Don't get the steering wheel or CD player/dash area wet....I just wipe those down with a rag. You probably don't want to hose the stock seats as they will take a while to dry. For the carpet....it just depends on how muddy it is. If it is not too bad, then wait for it to dry. Then you can just pick up or vacuum the dry chunks and wipe the carpet down with a rag. If it is real bad, you can take the carpet out and hose it down real well. If I do that I like to setup a fan on the carpet for a day or two so that it doesn't stink.
Or...my favorite way is just to leave the mud, so you won't feel as bad about doing it again next weekend.