need help on our first steps

I promise I'll read the docs, but I would greatly appreciate
a short road map for our very humble ambitions;
a small estore with

1. payment by CC (authorize.net) , paypal and check/mo

for our store, we've found that a simple linear function
cost = A * weight + B
works out very nicely .
for our 10 products of various weights
as long as the coefficients for "A" and "B"
can be set for 3 different shipping zones:
US,
Canada,
and everywhere else ( all by USPS btw)

So I'd like to have a "custom calc" of these shipping costs.
instead of going to the USPS server.

What modules need to be added/setup ?

Thank you,

cm

cmz:

I promise I'll read the docs, but I would greatly appreciate
a short road map for our very humble ambitions;
a small estore with

1. payment by CC (authorize.net) , paypal and check/mo

cm

Paypal is already integrated in the latest release. You just need to set it up in the admin area under modules---->payment. There is a procedure you must follow to get the API credentials, it has to be gotten from Paypal by logging in and click on PROFILE, then click REQUEST API CREDENTIALS. When you set Paypal up in the admin it will ask for all of that info. Then you set up paypal to send them back to your store in other options.

The authorize.net and credit card modules are in the same place: MODULES--->PAYMENT click it and then click INSTALL and follow instructions.