Video2brain has 1 hr 20 minutes of free video training by Todd Kopriva on optimizing After Effects & Premiere and systems for maximum speed.
Earlier resources by Todd and Mark Christiansen are still valuable — see Setting Up After Effects for Optimum Performance and Todd’s own outline of Adobe Help topics on the matter in optimizing for performance: Adobe Premiere Pro and After Effects.
To whet your appetite here’s Setting Up After Effects for Optimum Performance with 64-Bit Systems by Todd Kopriva from Adobe After Effects CS5: Learn by Video: