Practice with grammar. http://www.bbc.co.uk/skillswise/words/grammar/
Visit this site to practice your weekly spelling words! It's fun! http://www.spellingcity.com/View-user-profile.html?user=308754
Quiz for homophones http://www.bbc.co.uk/skillswise/words/spelling/recognising/homophones/quiz.shtml
Practice homophones. http://www.funbrain.com/whichword/index.html
More practice with homophones. http://alexandria-es10.lausd.k12.ca.us/Staff_Pages/Henry_Anker/Mr_Anker_Tests_New/Language/Homophones/Homophones_Set_01a.swf
Super, fun challenge for homophones. http://www.manythings.org/wbg/homonyms_2-sw.html
Practice tricky vocabulary words. http://wps.ablongman.com/long_licklider_vocabulary_2/6/1631/417669.cw/index.html
Practice it's, its, there, their, and they're http://grammar.ccc.commnet.edu/grammar/cgi-shl/quiz.pl/its_there_quiz.htm
Practice to, too, two http://chompchomp.com/hotpotatoes/wordchoice12c.htm
Here are some other resources that you can't find on the internet: School Library Local Public Library