How to create skills and drag them to slots.

Hello. So i am trying to create a loadout scene where the player can drag 4 skills of 18 to the 4 slots at the bottom right corner of the screen. I want the 3*6 skills to all be completely different skills like in a DOTA style game. When draging from the 18 skills to the 4 slots i want the skill thumbnails to be dragged with the mouse. How should i approach this. All i have right now is what you can see on the picture below. Thank you! Edit: Also how should i implement different cooldowns for the skills as well as a global cooldown that triggers whenever a skill is casted? And second thing: how to make the 4 selected skills carry over to the actual arena scene where the fighting takes place? ![alt text][1] [1]: /storage/temp/4097-unity.jpg