Learning a new language takes a lot of dedication, memorization and practice. You should practice every day to improve and perfect your language skills. Just doing work in class and homework is not enough, only practice makes perfect!
Here are some usefull websites to check out for practice:
http://www.glencoe.com/sec/worldlanguages/spanish/buenviajelevel1_2003/index.html
http://glencoe.mcgraw-hill.com/sites/007861790x/
http://www.studyspanish.com/tutorial.htm
http://www.trinity.edu/mstroud/grammar/
http://www.lingolex.com/spanish.htm