Ethiopic Language Learning Materials
Fontes Discenti Aethiopicam
Grammatica
Amharic Conversation for English Speakers - A Primary Book
Peace Corps Amharic Course (very nice)
Amharic Verb Guide
Dictionaria
Lexicon Linguae Aethiopicae
Tigrinya Dictionary
Tigrinya Picture Dictionary
Libri/Fons
Other Lists of Resources
Lexicity (Has resources for languages other than Ethiopic as well)