What I read? Here are some recommendation

java / android

Introduction to Java (Excellent)

100 QUESTIONS AND ANSWERS for Android interview

Data structures & Algorithms in Java

Android Programming The Big Nerd Ranch Guide (2nd edition)

Android Programming Pushing the Limits – Erik Hellman


An Introduction to Object-Oriented Programming with Java 5th Edition
Head First Java 2nd edition

OCA Java SE 7 Programmer I Certification Guide

Head First Servlets and JSP, 2nd Edition

Java EE 7

design pattern

  1. Design Pattern-Oriented Software Architecture(A System Of Patterns)
  2. Mobile Design Pattern Gallery, 2nd Edition
  3. Patterns of Enterprise Application Architecture

php / js

  1. OReilly PHPCookbook 3rd Edition
  2. Learn JavaScript and Ajax with W3Schools
  3. Professional JavaScript for Web Developers, 3rd Edition

database

  1. MySQL Cookbook, 3rd Edition

math

  1. Pre-Calculus
  2. Calculus
  3. Probability & Statistics for CS 
  4. Introduction to Linear Algebra

basic / algorithms

Algorithms (4th edition) (robert sedgewick and kevin wayne – princeton university, 2011)
Notes for the course advanced algorithms (January 2000)
Thuật toán
Algorithms – Jeff Erickson
Advanced Algorithms Lecture Notes (Periklis A. Papakonstantinou)

Data Structures and Algorithms made easy

C++ How to program (8th Edition)
Beginning C++ Through Game Programming 3e – Dawson – Course Tech (2011)
C++ CookBook
Data Structures And Algorithms in C++ Second Edition
Giáo trình C căn bản (HaNoi Aptech)
HeadFirst C
Illustrating C (ANSI_ISO version) – Donald Alcock
Sams Teach Yourself C++ in One Hour a Day 7th
The ANSI C Programming Language Ritchie & Kernighan
Thinking in C++ Volume 1
Thinking in C++ Volume 2

python:

1. Learn Python The Hard Way 3rd Edition

operating system:

  1. Operating System 8th Edition

other:

  1. Parachute 2012