For Extra Practice:
http://www.colby.edu/~bknelson/SLC/ Colby College offers many practice activities for several subjects from Spanish 1 to Spanish 4. The list of activities appears on the left side. On the right are several cultural activities.
http://www.quia.com/shared/spanish/ Quia.com offers games and quizzes made by teachers of Spanish. Type in what you want to practice under "Keyword" and then click submit. Types of games include: Millionaire Show (called Rags to Riches), Hangman, Battleship, and many more.
To look up a word:
http://wordreference.com/ Offers an online dictionary from English to Spanish and Spanish to English. Also allows you to create a free user name and go into the forums to question native speakers on how they would say something