If I were still homeschooling and had about 50x more patience (a girl can dream, can't she?) these are just a few of the blogs/sites I'd be all over:
Art and Nature
Nature Study - tons of links at the bottom
Sew Liberated - (used to be Montessori by Hand)
Art Projects for Kids
Handwork
Charlotte Mason Companion
Math
Murderous Maths
Living Math
History
Knowledge Web (by James Burke of Connections fame)
Hyper History
Writing/English
Print out paper
Sneaky ways to get kids writing
Creative Writing Prompts
A great resource page
Science
Homeschool Diner
And lastly, I'm wondering something -
How civics-literate are you?