Arriving at the airport
Based Upon information from Abha Light Foundation.
Here's what you need to know about landing in Nairobi:
The Postal Address of where you are staying.
YOUR AIRPORT ARRIVAL:
The price of the taxi is about Ksh 900-1200 (about 10-15 $ or E, £) for the centre of Nairobi. In case you don't find the driver (unlikely), look for the "Jambo Taxis" kiosk. Tell them who you are.
Now, at immigration, if asked, just say you are touring and visiting friends. Don't mention anything about treating with homeopathy when visiting.
At the airport customs, go to "green channel" and just claim "nothing to declare" and everything as personal items. I don't think you're bringing anything dutiable ... everything is personal -computer, camera, etc. - it's all OK. Still, pack your bags in such a way that anything that might look the least dutiable or "interesting" is stuffed at the bottom. If they ask you "what did you bring for your friends", say "nothing". Customs people are looking for something to squeeze (bribes) out of you but no need to give in to it. I doubt you'll have problems though.
Change a bit of money at the airport banks - about 50 -100$. You can change the rest of it in the city at a better rate. You'll change what you need as you need it.
Any currency of any country is OK. However, I think it's better to bring cash. Generally large bills- $ or £ or any currency- (ie 100's , 50's) get a better rate than small ones (20's 10's, 5's, 1's). Traveller's cheques are more hassle than their worth and you lose a lot in the exchange.
You can use your VISA or MASTER card at any ATM here. But there will be losses from the bankcharges and exchange rates.
IMPORTANT: If you are bringing US$ you must bring the most recent bills. Bills printed before year 2000 are not changed in Kenya due to counterfeiting.