We've looked into writing an importer for Readerware in the past but unfortunately their data is kept in a proprietary format which can't be parsed for importing. But you can import your data from Readerware into the Pedias via a tab or comma delimited export (both options are provided by Readerware). Just make sure you select all the relevant fields to be included in the export. The order of the fields is not important since you will be able to map the fields accordingly during the import into the Pedias.There are two drawbacks to this option though - as far as I know from users who previously switched from Readerware to the Pedias, there is no way to export the music tracks data and text based exports don't include cover images.
What you can do though is use the advanced info download option in the Pedias once you have imported your data. That feature will import any missing information, such as tracks and cover images, from Amazon or one of the other sites you choose. Try it out with a few entries at first in the demo version to see if that would be an option. (This will work especially well if your data came from Amazon and thus has the ASIN attached already and Amazon will know exactly what cover image and/or information to send.)
Once you've done the import, you can do a batch search for advanced information via the Advanced menu > Get advanced info or do individual searches by using the little gear button in the Edit window. The batch search is faster but the individual search will let you check the returned results and let you choose the correct one if there's more than one possible result. Again, if your entries have an ASIN then this isn't really an issue because Amazon will know exactly which entry you're looking for.