Kathy, that is great that things are working out for you so well. Shipping needs are different for every company but one must to stay on top of changes and be careful not to lock yourself into one carrier. A union strikes, bad weather, or even a single annual price change can change your business profits overnight.
Even though business outflows and costs are different, I think how you deal with shipping costs at a web site has some definite commonalities. For example, I think free shipping should be used to increase sales volumes at the time of purchase. Or, flat rate shipping should be used to increase market size.
Regardless of how you handle your shipping, I think it is very important that you let the customer know up front all the options. You should also look at people exiting from your web site from you shipping options page because that is no different than them leaving at checkout. And, you need to know when you are scaring off customers.
At least that is my two cents…
Bert at Harvey Software, Inc.
Multi-Carrier Shipping Software and Supply Chain Solutions for Internet Retailers
Also a provider of free shipping information and resources at Harvey Software`s Parcel Shipping Blog
along with free tracking solutions at TrackingPage.com