I've just bought an iPod Nano, and I love the form-factor. I am a little confused though, how to integrate iTunes with my existing record collections. Here's what I want to do:

I have all my CD:s ripped to lossless WMA or FLAC. (I use Squeezecenter to play them on my home-stereo).

Now, I want to make all the albums available for in iTunes, so that I can transfer them to my Nano. When I buy and rip a new CD to my record collection, I want this album to be available in iTunes, preferably automatically, or at least without too much hazzle. Lastly, it would be nice if album art is preserved.

In iTunes, I can add the root directory of my record folder structure. However, this first of all takes a really long time, since iTunes need to convert the files to MP3 (or whatever). Secondly, and more seriously, it seems as if there's no "rescan"-function, meaning that each time I add music to my record collection, I need to clear iTunes, and add all music again.

So I thought I would use dbPowerAmp to batch-convert all music to MP3 in a separate folder structure. However, I still don't know how to add this music to iTunes, without going through the same process as above (except it will be a little faster, since the files are already MP3).

How do people use iTunes in this scenario, and ideas?