For a small fee, ipasource.com will provide you with the IPA, word for word translations, and poetic interpretations of your foreign language song.
Amazon sells both audio recordings and sheet music. It also has access to sellers that feature used sheet music--a smart and effective way to save money when purchasing music.
This company has an extensive collection of sheet music for all instruments. If you're looking to purchase a single song or a complete collection, they should have it.
Whether you're working on a classical, musical theater, or jazz song, you may need access to a full accompaniment recording. This website site provides you with both an audio file and PDF of the sheet music for a small fee. An added benefit is being able to choose the key of your song.
If you don't have a piano or pitch pipe, these virtual keyboards are very helpful whether at home or while traveling. Several free piano apps are also available for download on your smartphone if you need more convenient access to pitch while on the go.
Youtube has an enourmous database of classical recordings and videos.