I've had my XL1s for over a year now, and I've strictly used the camera-mounted microphone up to this point. I'm ready to add a lav mic into my setup; with that said, can you give me some instructions on how to use both the on-board mic and the wireless mic at the same time? I'm really sorry for posting something that's probably been answered a million times - but with the xl1s watchdog & threads on here I've searched for, I tend to get confused reading about 16 bit channels vs 12 bit and those sorts of things. A wireless mic system is totally new to me. I have an MA 100 adaptor on the way, as well.

Here are a few specific questions:

1. I read somewhere that to use both audio sources, you need to push the "audio monitor" button to the "mix" setting and that you must do this every time the camera is turned on and/or goes into standby mode. Is there a different way? That seems rather repetetive ...

2. When wanting to use the lav mic with the on-board mic, do I plug the MA 100 jacks into the "video 2" inputs located to the right of the "phones level" dial?

3. What audio settings on the side of the camera will optimize the setup using both microphones??

Once again, I'm really sorry about such basic questions. I'm new, and trying to learn! Thanks!!!

If you want to use the onboard mic, you'll have to use the camera in the lesser quality of 12 bit/32k audio, because the on-board mic needs power. You could rig some wiring to power the mic and still input a second mic, but this isn't really a good option. You need to really move to 2 discreet mics vs trying to use the on-cam +lav.

I plan on using the camera for videotaping hunting scenes/footage. I will be filming over a hunters shoulder in a tree - I would mainly use the onboard for picking up the sounds of crunching leaves and such things. The wireless will be for recovery of animal and post-hunt interviews. Do you think a shotgun mic mounted to a tree would be better than the camera mic for picking up sounds on the ground??

I think in this situation a shotgun is more PITA than it's worth. I've done a couple hunting vids...
you'll be better off wearing a lav yourself, wiring that to the camera. Shotgun could also be mounted to a tree, but the closer the mic is to the sound source, the better it will be. A shotgun mounted on a tree will be a static mic, and you're after movement in timbre, depth, and impact.