Here is a brief - and not necessarily representative - selection of links.

JJ Crowder Masonic pages are particularly good.
Pietre-stones An enormous site, packed with information. A clear and comprehensive attempt to rebut objections raised by the 'Anti-Masonry' movement.
Freemasonry Watch The most well known of the 'Anti-masonry' sites. Apparently there have been several attempts by Freemasons to close this site down.

Vernon Jenkins has a fascinating site on Biblical gematria, 'The Other Bible Code'. His articles on the first verses of Genesis should be required reading for anyone wishing to consider themselves culturally educated. Vernon interprets the awesome mathematical mysteries that come to light from an evangelical stance.
Cnaan Aviv has an interesting site on gematria that includes an extremely useful calculator. It calculates Latin script words by Agrippa's gematria code, although he curiously calls this 'Jewish Gematria'. His calculator also produces figures for 'English' and 'Simple' gematria, but these are modern versions without historical provenance.

The Marlowe-Shakespeare Connection A great resource for new research on the Marlovian theory, edited by Carlo DiNota and featuring outstanding contributors. Unfortunately, it is no longer active.
Peter Farey Peter's website has been an excellent resource containing his own impressive research and a lot of extremely useful documentary material too. Sadly, Peter passed away in January 2020. This is now a legacy site that is being kindly hosted by the International Marlowe-Shakespeare Society.
The International Marlowe-Shakespeare Society This is the best overall source for information about Marlowe and his relationship to Shakespeare on the Internet. The Society and its website were created in August 2009 by an informal group of supporters of Marlowe's candidacy for the authorship of Shakespeare's work. They include(d) Peter Farey - Carlo DiNota - Isabel Gortazar - Daryl Pinksen - Mike Rubbo - Sam Blumenfeld.
The Marlowe Society The Marlowe Society is dedicated to preserving the memory of the greatest poet and dramatist prior to Shakespeare. Some members believe Marlowe was Shakespeare, too. There are interesting research articles and links, as well as full information about the society.
Ros Barber Ros Barber is the author of the widely acclaimed blank verse novel, The Marlowe Papers, which explores the Shakespearean afterlife of the poet. She has made many other notable contributions to the field. See her research output at her official Goldsmiths University profile.
PBS frontline The American TV channel's site that sprang up out of interest in Mike Rubbo's film. Lot's of information here and especially useful for educators trying to make Shakespeare interesting for schoolchildren.
Matthew G. Scarsbrook Matthew is an up and coming young screenwriter and novelist who has recently written a very interesting account of Shakespeare's role in Marlowe's last days.

Shakespeare Authorship
Diana Price has a site accompanying her excellent book Shakespeare's Unorthodox Biography - New Evidence of an Authorship Problem.
The Shakespeare Authorship Trust has great resources and many fine videos on its YouTube channel. Membership is highly recommended.