authorize.net arb setup

I need someone familiar with [login to view URL] arb system to help me set up my site to use this service. i currently have paypal pro reoccurring billing and am changing this before we go live with this service. i already have the code and just need someone to spend a little time helping me get it set up and working right. what we are doing is offering a membership service that is charged monthly. we will be giving 7 days free trial before the billing. i can change what i already have done per your suggestions. i am not looking for someone to do all the work for me. i just do not totally understand the arb system. I want to use the create subscription, cancel subscription and update subscription parts of there system. i woudl like to get this done between now and the weekend. 1 must speak and understand English 2 be available to talk via skype during normal US afternoon and evening hours. 3. must know the ARB system I will talk in pmb more about this.