Useful links for me...

For job interview preparation.

1. http://web.iiit.ac.in/~avidullu/pdfs/crack_the_interview.pdf
   
2. http://www.allapplabs.com/interview_questions/java_interview_questions_7.htm
3. http://www.foddalo.com/

Puzzles

1. http://www.techinterview.org/
2. http://onepuzzleaday.blogspot.com/
   

Good blogs to hang with.

1. http://billthelizard.com/
2. http://hbfs.wordpress.com/2008/12/23/the-10-classes-of-algorithms-every-programmer-must-know-about/
3. http://www.jasonernst.com/category/wireless-networks/
   

Find existence and formula for any sequence.

1. http://www.research.att.com/~njas/sequences/

Tutorials

1. http://www.w3schools.com/
2. http://java.sun.com/docs/books/tutorial/java/nutsandbolts/index.html
3. http://www.idevelopment.info/data/Programming/java/PROGRAMMING_Java_Programming.shtml