Fortunately, there's little you'll need to adjust on your Mac.
The Getting Started guides for ProTools LE and M-Powered will have a small section called "Apple System Settings for Mac OSX" (Also included below).

As always be sure to check your system for hardware and software compatibility by visiting digidesign.com
To ensure optimum performance with Pro Tools LE, configure the following settings before you install Pro Tools software.
To configure Mac OS X for Pro Tools LE:
1. Make sure you are logged into an administrator account where you want to install Pro Tools LE. For details on Administrator privileges in Mac OS X, refer to your Mac OS X documentation.
2. Choose System Preferences from the Apple Menu and click Energy Saver.
3. Click the Sleep tab and turn off the Energy Saver feature by setting the sleep features to NEVER.
4. Also in the Energy Saver feature, visit the Options page and look for a "Processor Performance" option. If present, change it from "Automatic" to "Highest."
5. Return to the System Preferences and click Software Update.
6. Deselect “Automatically check for updates when you have a network connection.”
7. Close the Software Update dialog box.
8. Proceed to “Installing Pro Tools LE” section in the Getting Started guide.