This guide is what i currently have used when playing Sinestro. He is a very squishy and slow Blaster, but can really put the hurt on people with his passive debuffs. So cause of this people will want to target you first. Like they would Blue Beetle. 

So cause of this you dont want to lane 1v2. Try to only 1v1 or have a team mate with you. 

As for the skills, that is just how i went about upgrading mine. It is totally up to you and how you play or how the situation is going. 

Items: (some of these I had Mods on to increase their effects)
Atlantean Seal. (Modded)
The reason i included the Atlantean Seal is cause it helps you if you need an escape. Poke the enemies with your W skill and run away with your E. Now this of course might now work against champions like AtGL or WW cause of their grab skills. So you'll have to be cautious of those champs. 

Dreamstone.
This is a good item to have for Sinestro cause you can easily burn through Will as your are laning. I often just buy the Tier 2 of it right away to keep my Will sustained. Plus the cooldown it gets at T3 and T4 is really helpful. Plus it gives you Power Armor which is good for Sinestro.

Cosmic Belt and Book of Eternity.
For the Power Penetration....lol really the only reason. Cause unless your team is all attack damage except you....the penetration really helps.

Cosmic Staff. (Modded)
1. for the cooldown it has, and 2. for the wounding and DoT it gives your skills. Which really came in handy for going against Bruisers and Enforcers.

Eclipso's Diamond and Neron's Contract (Modded Diamond)
These items give you some more defense, which for Sinestro is handy to have. Eclipso's Diamond came in handy really when i was lanning as i poked drones. But it also helps if you are running away. You toss your ult behind you at the chasing enemies and as they take that damage you get health.

Pandora's Box.
Mainly I would get this for the Move Speed and the Cooldown it gives.