Here are some collected maths webpages, archives and blogs, which make my daily life easier. You will find many more interesting links on any of them.

Mathematics Webs & Preprint Archives

The Transpennine Topology Triangle Homepage
http://www.greenlees.staff.shef.ac.uk/ttt/ttt.html
 
The British Topology Home Page
http://www.maths.gla.ac.uk/~ajb/btop.html
 
Hopf Topology Archive
http://hopf.math.purdue.edu/
 
Algebraic Topology Discussion List
http://www.lehigh.edu/~dmd1/algtop.html
 
K-theory Preprint Archives
http://www.mathematik.uni-osnabrueck.de/K-theory/
 
Arakelov Geometry Preprint Archive
http://www.institut.math.jussieu.fr/Arakelov/
 
Algebraic Geometry Sites
http://www.math.byu.edu/~jarvis/alg-geom.html
 
Categories List
http://www.mta.ca/~cat-dist/
 
Number Theory Web
http://www.dpmms.cam.ac.uk/Number-Theory-Web/
 
Mathematics ArXiv
http://front.math.ucdavis.edu/
 
xxx Mathematics ArXiv
http://arxiv.org/
 

Mathematics Journals Archives

JSTOR Archives
http://uk.jstor.org/
 
NUMDAM Archives
http://www.numdam.org/
 
EMANI Archives
http://www.emani.org/
 
MathSciNet Archive
http://www.ams.org/mathscinet/
 
ZMATH Zentralblatt Archive
http://www.zentralblatt-math.org/zmath/en/

e-Math for Africa                                                                                                         http://www.math.golonka.se/

LMS London Mathematical Society
http://www.lms.ac.uk/
 
AMS American Mathematical Society
http://e-math.ams.org/
 
EMS European Mathematical Society
http://www.maths.soton.ac.uk/EMIS/index.html
 
IMU International Mathematical Union
http://www.mathunion.org/ 

AMMSI African Mathematics Millennium Initiative

http://www.ammsi.org/                                                                                                                          

Mathematics Blogs etc.

Secret Blogging Seminar
http://sbseminar.wordpress.com/
 
Noncommutative Geometry
http://noncommutativegeometry.blogspot.com/
 
F_un Mathematics-ceci n'est pas un corps
http://matrix.cmi.ua.ac.be/fun/index.php/about

Rigorous Trivialities

http://rigtriv.wordpress.com/

Terence Tao's blog

http://terrytao.wordpress.com/

The polymath blog

http://polymathprojects.org/                          

The n-category cafe
http://golem.ph.utexas.edu/category/

Mathematics under the microscope                                                                             http://micromath.wordpress.com/    

This Week's Finds in Mathematical Physics
http://math.ucr.edu/home/baez/TWF.html

Juegos topologicos

http://topologia.wordpress.com/
 

Wikipedia
http://www.wikipedia.org/
 
Google
http://www.google.com