In Logic Express and Pro you can automate almost anything you like. Want the volume of a track to fade in? No problem! Want to control the frequency cutoff of your low pass filter? You got it!
Just enable automation mode: (keyboard shortcut A)
and choose what you would like to automate:
Then with the arrow tool, click to add new automation anchor points and drag them around as you like:
If you want to get all fancy, choose the automation curve tool and change the slope of the automation line:
Access more automatable parameters by going to the Arrange window View menu, and open the Hyper Draw drop down menu.