Here are some links to a few ACT practice websites:
Varsity Tutors: www.varsitytutors.com
ACT Video Tutorials: ACTprepVideos.com
More ACT Video Tutorials: sophia.org
Practice Tests for the ACT: Preparing for the ACT
Practice Problems from the College Board: collegereadiness.collegeboard.org
Test Anxiety?: https://www.mo-media.com/pdfview/?file=testanxiety.pdf
Should I Re-Take the ACT?: https://www.mo-media.com/pdfview/?file=retakes.pdf