complete a magento webiste

Myself and a freind have formed a company for an online fashion boutique. A developer has created a magento website for me but is unable to complete the job properly. For example does not know how to attach the correct links in teh cms boxes or doesnt know how to add writing to the slider, or add the correct quanities to items of clothing ect. The job is almost finished I belive but most importantly my business partner and I need a turtorial on how to operate the website ourself thereafter. A lot of out time has been wasted and we do not have any budget left but really need this completed as are serious about the business