Supporting a proposal on Hive does not cost anything to you. You do not need to delegate Hive Power or send HIVE or HBD. When you cast a vote for a proposal, you are essentially signalling your approval of the proposal and indicating that you would like to see it funded. This voting power is proportional to the amount of Hive Power you hold.

It's nice to get that explained.. I'm happy to support any development, but so far have shied away from proposals as I thought exactly that: It'll lower my HP etc and I didn't feel I had enough yet to support that.