There are few references right now on the web regarding LPG so I have started collecting them here.

• Using the LALR Parser Generator
• Using the LALR Parser Generator (PDF)
• Getting_Started_with_LPG (PDF)
• LPG Automatic AST Generation
• IMP LPG Help at the Eclipse Wiki
• More IMP LPG info at the old IMP site at SourceForge

*Note that these docs can be found on SourceForge