Joins
Inner joins are of the form where tbl1.col1 = tbl2.col1 or something like that, and does not not output rows that don't match. A LEFT or RIGHT JOIN does the same thing but shows records from the left or right table being JOINed. The term outer can be added after the words LEFT or RIGHT for ODBC compatability and does nothing extra.
Changing your password
mysql> set password = password('your_new_password');
Change a column type
mysql> alter table tblname modify colname coldef;
Adding Users (examples below)
mysql> GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP
-> ON bankaccount.*
-> TO 'custom'@'localhost'
-> IDENTIFIED BY 'obscure';
mysql> GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP
-> ON expenses.*
-> TO 'custom'@'whitehouse.gov'
-> IDENTIFIED BY 'obscure';
mysql> GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP
-> ON customer.*
-> TO 'custom'@'server.domain'
-> IDENTIFIED BY 'obscure';
mysql> GRANT ALL PRIVILEGES ON *.* TO 'monty'@'localhost'
-> IDENTIFIED BY 'some_pass' WITH GRANT OPTION
mysql> GRANT ALL PRIVILEGES ON *.* TO 'monty'@'%'
-> IDENTIFIED BY 'some_pass' WITH GRANT OPTION;
mysql> GRANT RELOAD,PROCESS ON *.* TO 'admin'@'localhost';
mysql> GRANT USAGE ON *.* TO 'dummy'@'localhost';
After each of these, I do a flush privileges. This is usually only if you insert or update the mysql.user table. Just a precaution for grant.