Best study method for remedial student

Can anyone recommend some tools for someone who is not up to speed academically yet for the usual ACT study guides? Student has plenty of time until he has to test but limited study hours daily. Goal is to start studying with the usual tools in 6 months or so after the foundational material has been covered. Most efficient methods that target ACT tested material at a lower level?
Thanks

Kahn academy offers help at every level. Start basic and slowly work your way up to the study guides.