Please thank YukiMizuno for the lovely icon!
Here is a list of helpful links and the different people who can help you with different subjects.
Math symbols to copy and paste here and here.
Find out what that particular word is translated into in five different languages here.
All sorts of useful math stuff including the integrator.
Older reference tools online, including a french-english dictionary and a really good thesaurus.
MissingHorcrux - Linguistics, MLA and Footnote Citation
sksyong - MLA Citation
MissingHorcrux - Algebra
kalany - higher maths, statistics
sksyong - Algebra, Geometry
EmzLovesHarry - Biology
MissingHorcrux - French, Italian, Chinese, some other languages
Etlu-Yume - Japanese
sksyong - French, Spanish
EmzLovesHarry - Italian
kalany - basic to intermediate level economics
SongThread - classical music