Welcome to MobileRead, Dozy!
Calibre is definitely the way to go and Kovid is wonderful about helping when we have questions as are many of our members here at MR. I have a Sony 700 and the information in both the
Sony 700 and
Sony 500/505 threads has proven incredibly helpful. I use Calibre to convert my ebooks into the correct format and to update the metadata and then use ebook Library to make bookmarks and annotations before uploading to my reader. Good luck.
Happy Reading.