Miscellaneous
MathArxiv. MathStackExchange. MathSciNet.
What is Algebraic Geometry? For bird's-eye view, see The Wikipedia. Also see MathStackExchange Answers.
History of Homological Algebra (An article which is written by Prof. Chuck Weibel).
History of Algebraic K-theory (An article which is written by Prof. Chuck Weibel).