Luckily, there's a wonderful piece of software available, known as Calibre, which is capable of converting the vast majority of the myriad ebook formats into the digitally signed .mobi format that the Kindle loves so much.
In addition to the conversion capability, Calibre is essentially an ebook library management tool similar to what is available for music files, such as iTunes, winamp, etc., with support for metadata, covers and so forth. It also has syncing support for a variety of e-readers, including the Kindle, the iPad, Sony's E-Reader and more, though some require additional software support.
As far as I know, Calibre is the only software of its kind and it is, thankfully, free, open-source and multiplatform. You can download it here, or from Ubuntu's official repositories. If you get it from the repositories, though, be aware that it does not come it's own copy of libunrar.so, which will cause it to choke on compressed archives, such as .cbr comic book archives and any otherwise compatible ebook files contained within .rar archives, usually with an error something like this:
OSError: libunrar.so: cannot open shared object file: No such file or directoryThis error will occur even if you the unrar and unrar-nonfree packages installed, and I am not aware of any packages that will provide libunrar.so. However, you can download a precompiled (32-bit) version here.
To install it, decompress the .tar.gz archive by right-clicking on it and selecting 'Extract Here.' This will decompress the archive into a directory that is misleadingly named libunrar.so (the real library binary is inside *that* directory). So, open a terminal, navigate to the newly decompressed directory and type:
sudo cp libunrar.so /usr/lib/After that, you should be ready to run by either choosing it from the 'Office' section of the Ubuntu menu or by typing calibre into a terminal.
Once you get it up and running, the preferences are extensive. You can choose how it interprets metadata from filenames (I still can't get this configured properly for some reason; it always either pulls the names in wrong or swaps the names and the titles), how converted books are formatted and an array of other options.
You can set up an email address (or use an existing email server) to send books wirelessly to supported ereaders, but be careful if you own a Kindle because Amazon charges for anything that gets emailed to your device (15 cents per MB at the time of this writing). This in mind, I'll be sticking with USB transfers.
My personal favorite feature of Calibre is the Web interface, which makes your library available to you anywhere in the world via Web browser. To set it up, you just turn on the included Web server via Preferences > Content Server and set up a username and password to use for login. If you have a dynamic IP address (as is the case with most cable internet), you'll also need to get a static IP address from one of the many providers, such as dyndns.com, and port-forward port 8080 through your router. This server feature works well with the minimize-to-the-notification-area feature, which makes it less obtrusive while running in the background.
Furthermore, for people with an iPad, the free ereader app Stanza can connect to your Calibre Web library to sync, which is very cool.
What with the conversion, organization and available-anywhere-there's-internet server, Calibre is a pretty awesome piece of software. However, I do have some complaints:
No native .doc support. It would have been really nice if Calibre could at least convert .doc files to other formats, presumably via an external library (similar to the rar support) or an API. Maybe the author could work out something like this. As it is, it just coughs up errors if you try to convert them and opens OpenOffice.Org if you try to view them.
Crashy as hell. Any time I try to do anything with a batch job, Calibre freezes and crashes. This is a serious annoyance, but I think it'll be fine once I get everything set up. I expect that, once I get everything tagged and converted to .mobi, I won't have to use any of the really destabilizing features--specifically, the batch stuff--with any regularity.