You only have to do this for one faction.
There are 7 skills for RDA and 8 for the Na'vi. Some of those skills have a very short cooldown time whereas others take pretty long.
For the skills with long cooldowns you are best off using the skill and then teleporting to another planet as then your skills will be recharged. Make notes of which skills you need to do and how many times you have used each skill so you won't forget. These skills must also be at max rank (4) so make sure you have enough exp points before you attempt this.
Here is a list of all the skills and what they do.
RDA
Skill Effect
Elite Traning Quick burst of speed
Chromatic Blend Sneak past enemies by blending in with the enviroment
Ultrasonic Repulsor A supersonic wave that is sent out that knocks back Na'vi and keeps creatures at bay
Genetic Regenerator Restores your health
Berserk Increases your damage for short period of time
Zeta Field Increases your resistance so you recieve less damage
Tactical Strike Calls in a air strike on your target inflicting large amounts of damage
Na'vi
Skill Effect
Kinetic Dash Run speed increased
Pandoras Union Sneak past enemies by blending in with the enviroment
Titans Bash A strong smash to the ground dazes your enemies and roots them to the ground making them easy targets for melee
Eywas Breath Restores your health
Whirl of Fury Increases your damage for short period of time
Pandoras Protection Increases your resistance so you recieve less damage
The Swarms Wrath An AOE ( Area of Effect) skill that damages enemies surrounding the player
The Beasts Aegis Summons a creature companion for a short amount of time to aid the player (Viperwolf at ranks 1-3 at rank 4 skill summons a Thanator which the player can ride on)