Time Series Tips
This is a good website for Time Series, in particular aspects of ACFs, PACFS, and ARIMA Models: http://www.duke.edu/~rnau/411home.htm
Below are some specific pages that I found helpful.
Determing order of AR & MA Terms from ACF/PACF http://www.duke.edu/~rnau/411arim3.htm
Determining a Seasonal ARIMA Model: http://www.duke.edu/~rnau/seasarim.htm#model1
General Guidelines for Determining ARIMA Models: http://www.duke.edu/~rnau/arimrule.htm