CRM insert record with relationship entities.

HI all,

I have relationship with multiple entities like parent  account entity with child entities (task,appointment contact).

I tried to insert record with following link  but not working ,i think that is for (M:M):
http://charanmandya.blogspot.in/search?q=associate

I am developing a html webform to insert data from html webform to Dynamic CRM using C# and everything will dynamic like parent and child entities as well as that's fields also. 

Thanks