Look for that elusive article on our site:
Micscape Magazine past issues online (read articles online using the original illustrated index for each month).
Article Library (browse articles by category)
Automated Search (a search engine for keyword searches in all articles)
Contributor index (a list of all Micscape contributors to date)

External Microscopy forums: Places to discuss the hobby or to raise queries.
www.photomacrography.net forums, galleries, articles on macroscopy and photomicrography.

groups.io (formerly Yahoo groups):
Amateur Microscopy
Diatom Forum
Microscopy as a hobby or profession
Wild Microscopes

Facebook groups:
Amateur Microscopy (>21000 members, very active). Also specialist groups e.g. for users of given maker's microscopes (e.g. Zeiss, Olympus, Wild, Vickers). Also try a Facebook Group search with keywords like microscope or microscopy to find these.

Other:
Microbe hunter the website ably run by Oliver Kim has built up a popular and valuable forum with help for both the beginner and more advanced user.

Listservers:
Algae-L 'Forum for marine, freshwater and terrestrial algae'. Access to Archives possible for non-subscribers.
Diatom-L 'Research on the diatom algae.' Access to Archives for subscribers only. Link was current March 2016. Many online diatom resources point to an outdated Indiana Univ. listserver. (With thanks to Rob Kimmich for the current link.)

Mikroskopie-Treff.de (Extensive German microscopy forum; some English categories.)
Mikrobiologische Vereinigung München e. V. Wide range of articles and resources in German.
Le Naturaliste French based forum and image gallery for micro / macro but open to non French speaking international contributors.

Other sites (also see Societies and Clubs page.)
Royal Microscopy Society Journal, 'infocus' and other resources for members and the community.
Quekett Microscopical Club Journal, Bulletin and meetings for members.
Light Microscopy Forum links and articles
Little Imp Publications public domain books collated by Steve Gill formerly on CD and now free on Micscape.
Mikroskop Museum German website with resources on microscopes / makers .
Molecular Expressions awesome optical microscopy resources
Dennis Kunkel's SEM images stunning images
Diatoms Ireland - resource site by Leszek Wolnik
Leitz museum an illustrated resource compiled by Robert Allen
Microbe hunter microscopy enthusiast website, forum and magazine edited by Oliver Kim
Microscopies online magazine and Forum for French speakers
Micrographia articles, projects for the enthusiast
Microscopy Today journal with online archive
Modern Microscopy online journal by McCrone Group
Fun Science Gallery projects, articles on optics in English and Italian.
Independent Generation of Research (IGoR) - Wiki style resource for citizen scientists to share their work.
Lens On Leeuwenhoek - extensive resource online by Douglas Anderson
Collected Letters of Antoni van Leeuwenhoek ('Alle de Brieven ..') transcribed and free online at DBNL.
A Cabinet of Curiosities a resource on Victorian microscope slides by Howard Lynk
Klaus Kemp's 'Diatoms' website - offers regional strews and arranged prepared slides of diatoms, an 8 form test slide, radiolaria, insect scales etc and prepares arranged slides on commission.
'Diatoms Ireland' resource by Leszek Wolnik
Historical makers of microscopes and microscope slides Brian Stevenson's extensive resource .
Victorian slide makers
Cambridge rocking microtome resources including manual
www.willemsmicroscope.com Dutch enthusiast Willem Cramer's website
David Jackson's Better Microscopy blog. Regularly updated free resources extending from his 'Better Microscopy' series of books.
Stefano Barone's Diatom Shop sale of his own prepared and arranged slides of diatoms, radiolaria, forams and scales.
www.testslides.com website devoted to Stefano Barone's Diatom Lab test slides.
Darwin Biological a UK company for 'biological education' supplies. Including live cultures of protozoa and algae.
Microscopie van de Natuur Dutch microscopy resource site by Rolf Vossen.