I'm not going to pretend that I have managed to get all the interesting information about Eleanor into the book, or even onto this website. Here are a few places where you can find interesting things about her or her family.
Eleanor of Castile Pages
Eleanor's wikipedia page: Don't sniff, it is really good. I strongly suspect it of having been substantially written by John Carmi Parsons, the foremost academic expert on Eleanor, and author of "Eleanor of Castile: Queen and Society in Thirteenth Century England". I generally think the overall impression of Eleanor is too negative, but it certainly provides a very good summary of the facts.
Kathryn Warner's summary : Kathryn runs a great blog devoted to Edward II, but has this excellent short page on Eleanor, and snippets about her elsewhere on the blog. She is also a great source for details about the later careers of Eleanor's children. Her biography of Edward II will be out in October
Eleanor Cross Pages
Last year I did an "Eleanor of Castile Funeral tour" following the route of the cortege from Harby to London, and evaluating a lot of the available material along the way. Links to those bits of the blog are under the headings of each cross
Museum of London: has a nice summary, and actually has some bits of the Cheapside cross
The Crosses' wikipedia page: is another good round up
Bob Speel's page: My personal favourite. Beautifully researched, with lots of historic images of the crosses
Blog post on the journey to Lincoln
Blog posts on the viscera funeral and the Lincoln Cross
Research Well Lincolnshire has a good summary of the limited materials on this cross
Blog post on the Grantham Eleanor Cross
Lincstothepast: This has a wonderful download about the Stamford cross
Blog post on the Stony Stratford Eleanor Cross
Blog post on the almost forgotten Woburn Eleanor Cross
Blog post on the Waltham Eleanor Cross
Our Broxbourne has a lovely collection of images of Waltham Cross. While it is now the least attractive of the crosses (a combination of development, pigeon protection and restoration) it was in the C19 the most picturesque of the lot, as it fought a battle with a neighbouring pub!
The Cheapside Cross
Touring the Crosses
If you decide to tour the corsses in person, these blog posts, plus Jean Powrie's book on Eleanor (which is really a Croos tour guide!) are your best bet. But you will also find good material including maps, if you are walking on The Queen Eleanor Cross Walk pages
Queen Eleanor Cycle Ride pages: The other nice way of following the crosses' path is by cycle. An annual ride organised by St Martins in the Fields welcomes full tour and day cyclists