How to Size Text in CSS – Richard Rutter describes various approaches for sizing web type in pixels, ems, and percentages. Rutter pioneered the “62.5% Method” for sizing web type, which I still use.

Five Simple Steps to Better Typography – Mark Boulton’s great blog post series on how to make the type on your website better. Nice, illustrated examples, very accessible to non-designers.

Compose to a Vertical Rhythm – Helped establish the use of a baseline grid, or vertical rhythm, for web typography.

Setting Type on the Web to a Baseline Grid – Wilson Miner shows you how to establish a baseline grid for your website, and how to make type of various sizes adhere to that grid.

Text Sizing – provides screenshots (lots of screenshots) of various browsers to compare text sizes.

I Love Typography – Not just web typography, but type in general. Beautiful site, lots of good coverage of all things type.

Web Design is 95% Typography – Great article that discusses the enormous role typography plays in web design.

Typography is the Foundation of Web Design – I couldn’t agree more with the title of this post. Samantha Warren discusses the process she uses for implementing great type solutions for the web in a presentation she gave at Refresh Baltimore.

The Elements of Typographic Style Applied to the Web – Great resource that takes Robert Bringhurst’s classic on typographic style and applies it to web design.

Web Safe Fonts – Great survey conducted by Jason Cranford Teague that details current web safe fonts and their presence on a variety of platforms and versions.

TypeTester – Lets you quickly and easily compare different typefaces and sizes, and generates CSS.

If you find any other useful resources, please share them!