Digitaldialects.com, ielanguages.com, Quiz-tree.com and Conjuguemos.com are good online resources for Italian vocabulary practice. These sites feature new vocabulary lessons, as well as activities and tests to aid in the memorization of the vocabulary.
Digitaldialects.com offers vocabulary practice for general phrases and greetings, including numbers, colors, animals, clothing and infinitive verbs.
Ielanguages.com features a number of basic vocabulary topics, as well as in-depth grammar exercises. The levels on the site range from beginner to intermediate. The site offers book recommendations, as well.
Quiz-tree.com features multiple-choice quizzes. The interactive site offers more than 20 quizzes on a broad range of topics.
Conjuguemons.com features more than 40 sets of word lists and flashcards for Italian vocabulary practice.