What's the best way to advertise/sell a whole bunch of books, CDs, and DVDs?

My friends J & P are downsizing from a very large house, and they've packed up over two decades of books, CDs, and DVDs to sell. Since they're ridiculously busy, they've made me a kind of estate agent: my job is to sell all this stuff, and then give them the cash (though I get a cut for doing the work, which is awesome). There's a wide range of quality and value -- some of the DVD cases are kind of battered; others are still sealed in the original plastic. Some of the books are ratty paperbacks; some are first-edition hardcovers.

My current plan is to build an Excel workbook that I can use to keep track of of everything that will be available, along with ISBN numbers for the books, release dates for the DVDs (and notes if it's a special edition, box set, blah blah), among other things. Then online research into fair prices for each of the items so that I know what to advertise as price (or what to expect from auction).

The problem is that there are so many options for how to sell this kind of stuff, and I'm at a bit of a loss to choose the best way (or ways) to do this. There's craigslist, ebay, and amazon, plus advertising the stuff on my dreamwidth, livejournal, and tumblr accounts (and then putting a link to those announcements on twitter). There are probably more I'm not thinking of, or don't even know about.

I have never sold anything on ebay, so my lack of familiarity with it is an automatic barrier to doing this easily, but if it's the best option for some of the items, I should probably look into it. But my understanding is that there are all kinds of fees and other details that make it sound like it's more trouble than it would be worth.

MY QUESTION:

Those of you who have done things like this--what do you suggest? What kind of success have you had in the past with the aforementioned venues for selling used stuff? What kind of bad experiences have you had? Do you have other ideas for me?

(Obviously I'll be making the Excel workbook available for download once it's finished for perusal by anyone who might be interested, so watch this space....)