Here are some steps and some articles to help you

Before you open the swimming pool you might want to read:
How To Prevent Swimming Pool Opening Damage

1)You will need to get the pump and filter going.You will need to prime the pump.
If you have a Hayward Super Pump This article will show you how to prime it:
Hayward Super Pump Repair Guide – http://wetheadmedia.com/hayward-super-pump-repair-guide/

2) Once you get the pump running you will need to shock the pool heavy:
Here are some articles about shocking your pool:
How To Shock Your Swimming Pool – http://wetheadmedia.com/how-to-shock-your-swimming-pool/
Liquid Vs Powdered Swimming Pool Shock – http://wetheadmedia.com/liquid-vs-powdered-swimming-pool-shock/
Swimming Pool Shock Buyers Guide – http://wetheadmedia.com/swimming-pool-shock-buyers-guide/

3) Next You will need to learn how to clear a green pool and you can find that article here:
Top Five Ways To Clear A Green Swimming Pool – http://wetheadmedia.com/how-to-clean-a-green-pool/

4) You will need to adjust your PH and ALK, This article shows you how:
Use Baking Soda In Your Swimming Pool – http://wetheadmedia.com/use-baking-soda-in-your-swimming-pool/

5) You will need to learn how to back wash your pool filter:
Complete Back washing Guide For D.E. Pool Filters -http://wetheadmedia.com/complete-back-washing-guide-for-de-pool-filters/
How To Clean Hayward Grid D.E. Filters – http://wetheadmedia.com/how-to-clean-hayward-grid-de-filters/

6) And then you will need to learn how to ad DE to your pool:
How To Add DE To Your Pool – http://wetheadmedia.com/how-to-add-de-to-your-pool/

let me know if the above helps you, If you have more questions please feel free to ask.