Hi,
Its not hard to find a house in Kampala or room sharing.
You need to get road side brokers for House/apartment on rent. They have lots of information and you dont need to pay them lots of money, just pay them 10,000 shs if they show you atleast 3-4 houses in a day (negotiate their fees in advance). You can also go to Property/Real Estate Agencies (now a days they are many).
Most effective way is to check the notice boards at the entrance of supermarket like Garden City (basement), Millenium & Checkers in Kisementi where ppl list their properties, cars and other items. You can also get house hold items from leaving expat.