When you connect the Everio to your Mac with a USB cable and power it on (check the Everio manual for proper settings) it should mount on your desktop like another hard drive. At this point you should be able to look at the files inside just like you do on your Mac. You should be able to click-hold on a mod file on the Everio window, a then drag it to your mac desktop to copy it.
As for the ".mod" files, I do know they are MPEG2 but not sure if they are a special "flavor." If you can view them in Quicktime using the Apple MPEG2 Playback component, then you should be able to convert them to a DV format for use in iMovie or iDVD using MPEG Streamclip. Find it at versiontracker.com.
Once you have converted the mod files to DV files, you can import them into iMovie or iDVD.
One BIG caveat. The ".mod" files on your hard drive are already compressed. You will be "uncompressing" (which takes time) and, if you eventually want DVDs, re-compressing (which takes even more time). This causes compression artifacts and a quality reduction. So while it is possible to use this camera with iMovie and iDVD, I wouldn't reccommend it beacuse of the quality reduction, extra time, and difficulty of use. iMovie and iDVD were really made for DV (and HDV) inputs. Though other inputs are possible, I feel that they are more for occasional use only. Just one opinion.