I found jobs from newspaper and website such as jobsearch and etc. How do i ask in proper way? what do i have to say? I know that this is so easy but actually its not. Anyway, I hope there is someone can help me please.

What do i have to say?
what do i have to ask? ofcourse about the job but should be more, i mean how to ask in proper way.
what necessary information i need to know?