One of the great things about adding technology to your website is the fact that the option to "outsource" the more difficult things to someone who has the experience to do it in less time that you ever could
When choosing a shopping cart system, I inform my customers to write out a list of the functions they're looking for in such a system, next research the various carts that fit the profile and then make an informed decision on which one best suits your needs not only function wise but buget wise as well (including outsourcing the project).
IF you don't have the $$ to make this work, simply choose one that offers a demo and/or tutorial that you believe you could learn without pulling out all your hair in the process