Many resources are available online to help students prepare for the ACT.
ACT's website www.act.org has practice tests and a question-of-the-day. This is a quick and easy way to expose students to the types of questions they will encounter on the ACT test.
There is a fabulous youtube channel that offers short videos with explanations about how to tackle the types of questions encountered on the ACT. The channel is KAPLAN SATACT. Here is a link to a sample video on the reading function questions:
The website www.thecriticalreader.com provides students with strategies to try to help them conquer the test. I found this tip to be helpful for those students who struggle to get through all 4 passages on the reading test to be interesting: http://www.thecriticalreader.com/general-reading-tips/act-reading.html. This site also offers practice on the most tested skills on the English test in their "grammar worksheets" section. These are not actual worksheets, but rather questions to answer online.