What graphic settings would you recommend for me with a GeForce GTX 650 with overdrive? I want to get the most out of the graphics card, but also don't want lag.  

I doubt that it makes sense to give recommendations for slider positions, especially with the GPU being the only info about your computer.

The best thing is to move the sliders step by step and compare the impact against the visual benefits. I know this is a time-consuming procedure, but I think it's the best, because it will always depend a lot on your personal setup, expectations and the combination of addons you use.

I would check out the AVSIM FSX Configuration Guide.  Link in my signature.

 

Best regards,

Look at the different guides, and do what works best for you. Find settings that you are happy with and stay there. Don't go overboard! There is no such thing as a perfect FSX, so you can be driven crazy if you try for such a thing.

If your using  any ORBX scenery, their manuals have recommendations for all ranges of CPU/GPU's. They seem to work well.

Alright thanks! I will take that into consideration.