I would like to list here a few Links, which I strongly recommend to visit.

QRP clubs
 
There are already QRP clubs almost in each country: the "crazy people", who transmit with 5 or 10 W around the world. And they also still united in clubs. Unbelievable (hi)!
 
If you have already envisaged to build a transceiver by yourself, those QRP rigs will surely be interesting for you. Get to know everything at the DL-QRP-AG (Working group for QRP and Self-Construction, in German) about availability of kits, tips and tricks i.e. in the FAQ (in German). The DL-QRP-AG also use a forum, by which you can clarify fast technical problems. In addition the DL-QRP-AG ships every 3 months the magazine "QRP-Report" (Directory as PDF) to its members.
 
Other QRP clubs:
 Alaska QRP Club
 American QRP Club (AmQRP)
 The Flying Pigs QRP Club International (FPqrp)
 Four State QRP Group (4SQRP)
 G-QRP-Club
 JARL QRP Club
 New England QRP Club (NE QRP)
 New Jersey QRP Club
 Northern California QRP Club (NorCal)
 QRP Amateur Radio Club International (QRP ARCI)

Other QRP stations
 
An incomplete list of people, which carry the QRP thought in the heart. The order is not an assessement. It's only an alphabetical order.

QRP equipment and kits
 
You can purchase QRP equipment and kits at the following manufacturers and dealers.

Electronic elements
 
The following dealers offer electronic elements to private individuals.

Antennas and masts
 
Antennas respectively masts are available at the following dealers.