Im getting increasingly confused by this whole process

If you submit the application online, then do you submitt all the supporting eveidence by mail separately?
From Visa4UK quote
"once you have applied online you must submit the application either by mail or using a courier/agency with your supporting documents to the appropriate consulate"
So where it says "submit the application" that means the one you just filled out online??? You have to mail it in again??
This site (visa4UK) is not very clear at all on this.
Then there a link on there saying click here for payment OPTIONS - so you click it and there's a long fee list, but no payment options, just a list of fees and some mail handling charges which I also dont understand if that applies to me (aaggrrr!!)
It also says that all person checks/company checks will be refused so what are the payment options supposed to be when they dont offer any alternative than paying when applying online?
Can someone pleeeeeeeeese shed some light on this - I dred the though of sending my VAF4 to the wrong place
my husband is in Florida and so will need to send it to Chicago - right?
I hope this doesn't mean he will have to go there for an interview!!