Ask each of your references how they would prefer to be contacted, and provide that information. Make sure that all of that contact information is current and valid (working phone numbers and email addresses, for example) each time you provide it.
Otherwise, you risk giving your prospective employer contact details for your references that they don't want used for that purpose (uncomfortable for them), or outdated information - which could prove embarrassing for you.
It depends how you are submitting this. Many of the contact forms I have filled out are online and were the usual name,phone,email and often their employer. But the key is to give a method of contact that the person will answer. If they live with their smart phone in their hand 24/7 then that number is the one to give. If they are are on Outlook all day and all night, then give their email. The people who you are listing should be expecting the company to contact them so when you call them to inform them they are references you should ask them what the best method of contact is.