First of all you need to know your requirements well. Some of the questions you should have answers on:

• Do you need members ares and/or playlists that require authenticaion/authorization or do you need to broadcast password protected streams?
• Do you wanna use Digital Rights Management (DRM) protection instead of password protection?
• Do you wanna install and support your own streaming server software or do you need a web-hosting with streaming video support?
• Do you need a streaming server software for Windows or Unix? Does it really matter for you?
• Do you wanna protect your streaming videos from recording (streaming videos can be recorded by screen video capture software anyway, but there are streams like mdatrtsp QuickTime streams or MoveNetworks video streams that currently can't be ripped/downloades/save by streaming media rippers) or do you wanna restrict content usage for non-members.
• How many viewers do you expect to have?