most use e-bay.com I think but them again most view several. Select the ship worldwide option, your auctio item will then be shown on alol the ebay sites..
as for starting price or reserve depends how much the record is worth and what you are prepared to let it go for, there is a charge for reserve price listing.
Days - select the length of time you require, standard is 7 days.
You can also select method of payment, cash, paypal, cheque, bakers draft etc. There is a charge for paypal. Go to ebay, there is a comprehensive "help" guide to listing your record.