Getting Started -
The Slayer Tower is the only way to train Slayer. Every monster inside gives XP, and no other monsters will let you train that skill. You can get there by using the Teleport in your normal magic spell book.
The Slayer Tower has 3 floors, each is lined with different monsters, going up in level required to slay them.
Suggested Equipment -
55 Magic - Alch
80+ Combat (Good armour and weapons)
43+ Prayer (Protect from mele)
Monsters -
I suggest you always kill the monster with the highest required level.
Crawling Hands - Level 1
Basilisk - Level 30
Jelly - LEvel 40
Turoth - Level 52
Dust Devil - Level 65
Nechryeal - Level 80
Abyssal Demon - Level 85
Dark Beast - Level 90
Conclusion -
Slayer is a great method of money as it can provide many rewarding and rare drops. Getting 99 is worth it because of the total amount of money that you can accumulate during the process, and to be honest, the cape is sweet.