It is appalling, appalling, I say, that I haven't posted anything language-related for over a month. Taken as I am by the blandishments of food and travel (in that order).
To make amends for my shameful behavior, here are two very useful sites for those who are studying or reviewing Italian, and they are completely free. Gratis!
From the University of Victoria in Canada, a good little set of self-correcting exercises on grammar, vocabulary and sentence translation. The level is quite basic, so that it will be suitable for those who are beginners or who are reviewing their knowledge of the language.
The oddly-named site ilgur.com (sounds like something from a B horror movie) is kept by an American who knows Italian well. There will be some imperfections, but overall it's a useful resource. The site is actually a blog and has comments activated, so that you can ask questions. It was originally set up to deal with grammar but has since been expanded to other areas.