this is simple to do...but can be complex to explain because there several different ways to go about it.
Transferring Info
you can transfer info from the PC2 different ways:
1. Connect unit to PC via AC/PC adapter. this can make a lot of sense w/a smaller unit that you take on and off the boat every time you go out. you don't need a separate card or card reader, just the ac/pc adapter which powers the unit and connects it to the PC.
2. Blank Card/USB reader. this is most likely going to be the way you want to go because you leave the unit on the boat and just take the blank card out. the data transfer from the PC is much faster this way too. keep in mind that you can transfer waypoints/routes/tracks both ways w/the blank card. i.e. you can write to the card with the unit (save waypoints to card), and then review them on the computer and vice-versa.
Software management of data
I'll group these options into 3 categories
1. Garmin Trip&Waypoint manager software. this is inexpensive and has basic cartography. this is the way to go if you already have your waypoints and just want to transfer them to the garmin unit.
2. Garmin bluechart cd-rom. this more expensive (street price of ~$100 for an area), but has fully detailed cartography. you can still transfer known waypoints/routes but in addition, because the cartography is fully detailed, you can plan new routes on the computer, taking the time to make sure you are navigating around any charted hazards etc. the software also can be a useful reference if you're just curious about a certain marine area. i have this software and love it. actual trasferring of info from/to the unit is the same as #1.
3. 3rd party software such as maptech. i am not going to elaborate because i don't know much of anything about them except that they are out there.
hope this helps