Your first line of defence is the Special Grammar Unit created by the Department of English.  And your second line of defence is Acadia University's Writing Centre. Other useful pages follow.

• MLA Online: A Guide for Research Papers -
• Vaughan Memorial Library Citation Guides
• Strunk's Elements of Style
• Hypergrammar
• The Nuts and Bolts of College Writing
• Punctuation Made Simple
• Guide to Grammar and Writing
• The UVic Writer's Guide
• Big Dog's Grammar

• Oxford English Dictionary (must be at Acadia to use link)
• Merriam Webster Online Dictionary
• Rhyming Dictionary for you budding poets