A hybrid web meeting is when you have two or more people physically located together meeting with one or more separately located people via a web meeting technology. The most frequent issue in this situation is that the group that is physically in the same space forgets about the needs of people online.
With a technology like Google Hangouts or Skype where everyone has equal rights in the meeting, you need to avoid microphone feedback. In the group location, either:
Have one computer designated for sound - use this for both microphone and speakers. All other computers should have their mics muted and speakers turned off. A great tool to allow for a group of ten or so to be easily heard is a USB conference microphone or USB conference speakerphone that can be attached to one computer, such as this one.
OR have everyone in the group equipped with USB headsets with microphones.
Good practice guidelines
Make sure everyone can hear you.
Use a microphone when you speak.
Make sure the microphone is on and close enough to pick up your voice, no matter what location you are in.
Don't have side conversations.
Make sure everyone can see you (if cameras are being used).
Sit in good lighting.
Arrange yourself and the camera so you are fully visible.
In the group location, if you only have one camera, at least once turn the camera around the room (even if it's on a laptop) so everyone can be seen.
Don't be distracting.
If you aren't talking, mute or turn off your microphone.
Avoid noisy activities like typing while your microphone is on.