Other
Clear Ink/spell Web: Let the Web Decide!
A different type of spell checker, giving results from search engines, not based on dictionary word lists, but on frequency of use on the Web. If you're looking for a word that hasn't become official or want to see whether one...
Other
Blue Book: Hyphens
This site from The Blue Book of Grammar and Punctuation contains seven rules for correctly using the hyphen, along with examples for each of the rules.
ClassFlow
Class Flow: Spelling Mistakes
[Free Registration/Login Required] Pupils will learn to identify spelling mistakes in sentences with this flipchart.
Other
Sweet Briar College: Common Writing Errors
This list from the Sweet Briar College of sixteen common writing errors makes an effective proofreading checklist. Examples of errors and corrections included when appropriate.
The Write Place
Literacy Education Online: Using Spell Checkers
This resource gives three pointers for getting the best results from your spell checker.
Other
Stage Door: Word Traps
This reference guide helps to discriminate words that confuse people with their spelling or meaning.