When/how to prepare and take act?

<p>I am a junior and have taken both practice act and sat tests, I scored much higher on the practice act and preferred the way the act was set up, therefore i plan to take the act, but... i am taking trigonometry second semester this year, so i was wondering when you would suggest i take the act (especially since i heard that certain times of the year have less generous curves for the test).
Also, how far before the test should i start studying and with what (online sources are welcome as well).</p>