I have studied some basic homological algebra. But I can't send to get started on spectral sequences. I find Weibel and McCleary hard to understand.


Are there books or web resources that serve as good first introductions to spectral sequences? Thank you in advance!



introductory book on spectral sequences
Many of the references that people have mentioned are very nice, but the brutal truth
is that you have to work **very hard** through some basic examples before it really makes
sense. 


Take a complex $K=K^\bullet$ with a two step filtration $F^1\subset F^0=K$, the spectral
sequence contains no more information than is contained in the long exact sequence associated
to
$$0 \to F^1\to F^0\to (F^1/F^0)\to 0$$
Now consider a three step filtration $F^2\subset F^1\subset F^0=K$, write down all the short
exact sequences you can and see what you get. The game is to somehow relate $H^\*(K)$
to $H^\*(F^i/F^{i+1})$. Suppose you know these are zero, is $H^\*(K)=0$? Once you've mastered
that then ...


