How to easily find whether the contibuted modules have been updated or not?
If you are going to attempt an upgrade from D6 to D7, you really should consider using Drush.  Really strongly.  The Drush Site Upgrade command will save you a lot of time, and as a bonus, it will tell you the upgrade status of your D6 modules, and will recommend alternate modules for some modules with no upgrade path, but for which alternatives exist.

If you really don't want to use Drush, you can use the Upgrade Status module.  It also has an upgrade assist block that will help you walk through the upgrade process manually.