Often a succinct search will yield the information one is looking for. Two good places to search include the documentation and the user forums/MathGroup archives.
For example:
The following Google search string will find, due to the structure of WRI's website, information about the function NVariationalBound:
NVariationalBound site:documents.wolfram.com inurl:mathematica
Another example:
The following Google search string will find information about asserting variable assumptions inside the user forum and MathGroup archives:
assumptions site:forums.wolfram.com
I hope that users who want to help other users in real time will list themselves here.
Chris ChiassonLucB can be contacted as "MaxisLuc" on skype (http://www.skype.com)
When no one is listed here, you might want to use one of the following distribution list that provide support for mathematica:
mathgroup@smc.vnet.net
groumf@ujf-grenoble.fr (GROupe des Utilisateurs de Mathematica Français)
or contact directly Wolfram Research at support@wolfram.com.