MySQL cheat sheet & examples, a list of useful mysql commands provides you the most commonly used.
Show all databases
mysql> show databases;
Create Database : create database cake_blog; 
Use Database: use cake_blog;
CREATE NEW TABLES 
Create table posts(
    id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY, 
    title VARCHAR(50), 
    body TEXT, 
    created DATETIME DEFAULT NULL, 
    modified DATETIME DEFAULT NULL);
INSERT DATA 
INSERT INTO posts(title,body,created) 
VALUES ('The title', 'This is the post body.', NOW());
ALTER TABLE : ADD & DROP COLUMN 
ADD COLUMN : ALTER TABLE users ADD group_id INT(11) NOT NULL; DROP COLUMN: ALTER TABLE users DROP role;
Show columns from table: SHOW COLUMNS FROM users;

 To discover the character set and collation of a database

Readmore: http://en.wikibooks.org/wiki/MySQL/CheatSheet