First things first, on arrival customs seems incredibly straight forward - the airport is well laid-out and sign-posted and if you are just transferring they have a shortcut which avoids needing to even enter the UAE. The queues are well separated so that those who do not need visas can quickly get through without having to wait for others. As a UK citizen, I was allowed 30 days from arrival for free and I had been slightly worried due to getting an Israel stamp in my passport (quite a few muslim countries do not recognise Israel so this incurs the wrath of the border guard and you will be sent packing in neighbouring Syria, Lebanon as well as Saudi Arabia, Sudan, Yemen and most likely Libya, Algeria and Mauritania, I've also heard Malaysia and Indonesia don't like it either), entering the UAE was no problem with this at all - although the border guard did make sure he stamped the UAE stamp aggressively on top of the Israel stamp lol.
The first section of departures has a small McDonald's which is probably the most affordable and filling food in the whole airport. There are so many flights to India and so many people waiting close to Arrivals that you could be forgiven for thinking that you actually were in India. I didn't really bump into more than about 2 European folk which did give it a bit of an odd feeling and I did get the occasional stare, although that could be due to the sun burn and greasy hair I was sporting at the time!
There are numerous exchange offices and bank machines in every little section of the airport, the staff are very polite - if so a bit too much! Seeing all the exotic destinations available at bargain prices was really quite mouth watering and I think few would go there and not start thinking about their next trip! I was starting to look like a member of the ginger taleban so decided to start shaving away at one of the sinks in the toilet, I certainly wouldn't recommend doing this - having shaved the majority of one side, I looked in the mirror to see a group of men disapproving my actions and looking more pissed off than I've ever seen the arabs, a member of the public (who I think was Saudi) in particular told me I couldn't do it and that it's not allowed.
The toilet attendant (young Indian) didn't seem bothered one bit and also faced a tirade from the same chap. I tried to convince them to let me shave off the other side but it clearly wasn't going to work, so I left with the most ridiculous facial hair style known to man (one side bearded, one side more or less fully shaved except for what might have passed for a curved side burn) much to the amusement of some children in one of the halls. Later, I made do with a dry shave (fortunately the razor was really sharp) in one of the toilets to attempt to tidy it up - it bloody hurt. So my tip is keep your beard or risk looking weird! Apart from this bizarre incident, it was a very, modern professional airport with a high level of efficiency and courtesy.
The choice of Duty Free upstairs after check-in was superb and this room (the departure lounge) was filled with people from all over who were waiting for visas (the visa staff were on a 2 week holiday)
As for leaving the airport - there are taxis to Dubai and Sharjah. It's about 30Dirhams to Dubai.