Yes. You may have to mess about a bit connecting your VCR to your camcorder (radio shack sells s-video to component/whatever connectors.). You won't be able to control the VCR through the firewire like you can your camcorder, so just "capture now" when you see what you want. Quality isn't so great depending on the source and quality of the VHS, but it's fine for casual use. If you want to make it a little simpler just plug the VHS into the camcorder, record onto miniDV, then you can control the camcorder with the miniDV as you would normally. No big deal either way as long as your camcorder has some sort of input other than firewire (most do).
If your DV camcorder has an A/V input then you should be able to transfer your video from VHS to the camcorder.
If your DV camcorder also has a firewire connector then you should be able to transfer your video from camcorder to Mac.
If, in addition, your DV camcorder is capable of analog to digital conversion, then you should be able to transfer your video directly from VHS to Mac through the camcorder as described in the previous response.
The DV camera that a person such as yourself will be using for digitizing material (video clips) to "the emac" must have analogue inputs and a fire wire port, think of the DV camera as an analogue to digital converter. This means you only need to pass any analogue signal through the DV camera and it will then go from the DV camera to the emac via the fire wire cable. Check what capabilities your DV camera offers and then you will be able to do your editing. If you have an old DV camera you may not be able to input an analogue VHS signal (or any signal) into/thru it. Then you will need to rent or buy a DV camera that will allow you to do what I mentioned above.
On another point, it's probably a good idea to transfer all your old VHS, hi-8 or Video8 footage to mini DV so that you have a digital archive of your presious footage. Keep all your original source tapes though. Remember miniDV is a compressed format. This means that there is a generation loss of quality when the transfer is done. Hi-8 in my experience looks better than most miniDV. VHS & Video8 usually looks about the same or worse than miniDV footage.
The only DV footage that looks very good to semi-pro is a DV camera that offers 3 chip recording capability and DVCAM (almost 2xminiDV speed) record speed. But these cameras usually sell from 3000.00 to 6000.00.