shipping explained ?

Hi

Just installed opencart.
I've looked at the online manual but does'nt say much about shipping. Does anyone know of anu good resources that explain how this works.

I activated royal mail, first class recorded and standard parcel.
Why is it that depending on weight first class or standard parcel disapear from the shippping page frontend?
Do the prices come directly from Royal Mail as and API ?

Thanks

If you look in catalog->model->shipping->royal_mail.php you will see that the rates are coded into the script, so it's not 'live' data - which is an issue since Postman Pat put his prices up this week. I'm currently trawling the RM site to get an updated list but they keep it well hidden, preferring you to enter details of your parcel (weight/size) and then chucking you a quote for the various classes of service. If I find it I'll post an amended royal_mail.php file for others to use here (unless someone knows of one lurking elsewhere in the forum?)