How to install cyanogenmod on LG P690 optimus net: how to know which ROM? I would like to install an android 4.x ROM on my Optimus Net (P690) Android 2.3.4.

When I go to the CyanogenMod downloads page at http://get.cm I see various phones but not mine. However this youtube video shows that such an installation is possible. Alas this page does not show where to get the ROM image from.

Could anyone suggest where to get it from?
The YouTube video refers to an XDA page as shown below:

That XDA page gives further details about the CM9 ROM, GApps and instructions.

Your LG P690's hardware seems to be a close match to my LG P500. So, if you are not satisfied with the ROM mentioned, you can give a shot with LGP500's ROM - the chances of getting it working in your P690 is good. Please search this site for details on knowing from where to download ROM for P500.