BeX Query creation Scenarios?

[CoolCaptain]

How many ways we can create a Bex Query? I mean to say, different Infoproviders used to create a BexQuery? I'm very confused in Creation of Bex Query from Infoproviders. Can Some one come up with a nice screen shot tutorial for every infoprovider? I will be very much thankful to them and moreover detail explanation of BeXQuery and its properties (??) like Characaterstics, Key Figures..so.on..

If Infocube contains dimension tables and a fact table, I can understand it is just like a database (In laymen terminology ) and very happy to say, creation of Bex Query is some what reasoning..

but InfoObjects are just fields and how come one can create a Bex Query from just InfoObjects? Can some one clear me regarding this scenario.. (:confused: )
and also please guide me how to create a Bex Query from virtual infoproviders like "Infoset" and "MultiProvider".. Please..

I have knowledge on Business Objects and its Universe which is useful in generating Reports, Dashboards and Scorecards. But I'm unable to digest (Understand ) BexQuery terminology to continue with this?

I hope I get a reply with either detail info navigational links or answered here with different scenarios with screen shots.. Please Guys...