P22 is an independent foundry specializing in historical letterforms that were previously unavailable in digital format.
MyFonts is a distributor of digital fonts from many type foundries in one easy-to-use Web site. It also includes a useful type identifier, What the Font, that searches for fonts provided for purchase on the site (see type identification).
FontShop is claimed to be the original independent font retailer. They produce the FontFont typeface library and have cutting edge fonts with some European influence.
FontHaus offers useful content, easy font finding features, a huge selection of name-brand fonts, font compilations, and libraries. They have been offering fonts since 1990 and are a popular resource.
Adobe has immensely influenced the evolution of digital type. They offer PostScript, Multiple Master and OpenType formats. Their collection is comprised of many graphic standard types.
Linotype offers quality fonts and is well respected in the design community. They have existed for over a century and have adapted well to new technologies.
What the Font is a type identification tool where you can upload a file and it will do all the work for you. It is limited in that it only searches for fonts in the MyFonts foundries and results are not always on the dot.
Identifont is another font identification site. This site comes in helpful if you are looking for a font that has certain qualities or is similar to a font you want to work with.
Typetester is a useful site for comparing screen fonts.
Designer Plaything is an all in one typography testing tool. It allows designers and clients to experiment with different web typography and color combinations and can be used offline with a downloadable application.
FontExplorer X is a font management software created by Linotype available for Mac and Windows
Typeradio is an online radio station airing interviews and the latest news in typography.
Typophile is a forum dedicated solely to typography. It is easy to get answers and opinions from experienced designers. It also serves as a news and type identification resource.
Adobe also has a user to user forum partially dedicated to typography.
I Love Typography is an inspiring, fresh, and interesting blog by John Boardley. Boardley is a graphic designer, web developer and writer with a passion for typography.
Typographica is another well-known blog featuring news and commentary on fonts and typography.
Fonts In Use Great source for research & inspiration. You can sort by industry, format & typeface, and make sure to click the “more” expander.