There are considerable online resources for notation. Stanford University has an excellent page of links to many different examples. Don Byrd's pages on extremes of musical notation are also useful. A more basic series of lessons is offered at MyMusicTheory.com
Also very useful for the orchestrator are the online fingering guides, for example:
Brass Instruments Fingering Charts
A Musical Playground for Kids: Music Theory Lessons (with thanks to Julie Miller).