Thought it might be useful if we share our top 3 sites that we find useful. Perhaps add to this list and don't add duplicates if possible. Mine follow:
1) Option Strat (free & paid) - allows your to build option trades and gives a great visual representation
2) Option Seller ROI (free) - provides a scan of top ROI for covered calls and cash secured puts
3) Finviz (free & paid) - great site for all round investment / trading information