Amazon's Kindle reader supports a variety of file types in addition to the proprietary .azw format. Text files, MOBI files, and even PDFs all are readable on the Kindle. Although PDFs are supported by the Kindle, they can be problematic to read. First, a handful of obstacles might be encountered in the file transfer process. Second, the PDF itself may not render in the most readable fashion. You can easily avoid both of these problems.
When uploading files to your Kindle, place them in the "Documents" folder on the device. If you place them elsewhere, they will not be detected as books. If you wish, you can organize them within the "documents" folder in subfolders. These subfolders will not be detected by the Kindle but may help for your own organizational purposes. In order to avoid misplaced books, you can use approaches such as the free Calibre program or Amazon's Kindle email service to send the files directly to the "Documents" folder.
Navigating your library on the Kindle can be difficult. Even if you upload a PDF onto your device correctly, it may be difficult to locate. In order to make your Kindle easier to navigate, organize your books within collections. You can group all books by the same author together, for example. Furthermore, you may wish to edit the tags of the items before uploading them to your Kindle. This will display the author and title information in a straightforward way. You can edit and organize tags through the Calibre program.
PDFs with Images
Many PDFs with images do not render well -- or at all -- on the Kindle. For example, if a PDF consists entirely of scanned images, it may appear as a file on the Kindle but its contents may not show up. In order to solve this problem, you may need use a program geared towards portable reading devices. In a program such as Calibre, a PDF-to-PDF conversion usually renders the images readable on the Kindle.
In addition to PDF-to-PDF conversion, it can be wise to convert your PDFs into a more Kindle-friendly format, such as MOBI. Free programs such as Mobipocket Creator, PDFRead, and Calibre support this function. Through this process, you can customize the tags and cover image for your books. This is a useful process because, although the Kindle does support PDFs, PDF formatting is not designed specifically for the Kindle. On many PDFs, highlighting and note-taking is either problematic or impossible. If you convert PDFs to MOBI, you will be able to highlight and annotate easily in your documents.