I think you should first disclose if the funds you are raising on this site will be used to further educate your students....or buy you a toy? It may not be my business but I think if you clearly state this on your site you will be less likely to offend your participants.
I think you would do well to place a counter on the page, along with a disclaimer, showing the total funds YOUR VISITORS will be generating for your STUDENTS.
That being said I think your site is a little too simple. The page needs to be resizable to fit screen. It currently is too wide. The title cells need more cell padding and or cell spacing. Your PPC google ads should be placed at the bottom of the page. The art, you title your site after, is absent and obviously disappointing. "Art Show Central” is devoid any art yet full of PPC ads links. I think a more transparent policy on the ad rev is in order. And a secondary even tertiary importance should be placed on the ad rev.
Perhaps some free resources for you students to actually use would be helpful. Some interactive use like Tutorials, links, Articles, Forums, Contests… Art etc .... A student/artist of the month contest would be cool. With a picture, bio or profile page. Something like that could spark an interest. If you provide these features to your students they may participate. Otherwise you simply have a PPC site. In My Humble Opinion.
Good Luck
PS
I was voted most artistic in my High School ( Las Vegas, NV )
namenut