Internet Shakespeare Editions
http://internetshakespeare.uvic.ca/index.html
A good and fairly accurate site on Shakespeare, containing a good reading list with many useful works.
The Dramatic Works of Ben Jonson
Digitized online version of all of Jonson's plays and those of his contemporaries, Beaumont and Fletcher. Not too easy to read, but a very valuable resource which is also printable.
The Holloway Pages: Works of Jonson
http://hollowaypages.com/Jonson.htm
An online version of all of Jonson's works, taken from the 1692 edition of Jonson's Works (the first folio edition to be combined in one volume), with the exception of The Case is Altered and Eastward Ho, neither of which appeared in the folios (both are on the site, but in different versions). Not an academically edited text, but this original might be interesting to compare with an academic version.
Poets' Graves: Jonson
http://www.poetsgraves.co.uk/jonson.htm
Information about Ben Jonson's grave and the inscription on it.
The Alchemy Website
http://www.levity.com/alchemy/jn-alch0.html
A website packed full of excellent resources about alchemy as a science, which also contains some (fairly limited) commentary on Jonson's play and a searchable online text.
Ben Jonson
http://www.hoasm.org/IVM/Jonson.html
A good online biography, taken from an academic publication.
Shakespeare's First Folio
http://shakespeare.palomar.edu/Folio1.htm#Beloved
The preface to Shakespeare's First Folio by Ben Jonson, which includes the famous lines, "He was not for an age / but for all time."
The Cambridge Edition of the Works of Ben Jonson
http://www.cambridge.org/uk/literature/features/cwbj/introduction/default.htm
The foremost scholarly edition of all of Jonson's works (forthcoming).