ですね is used similarly to "isn't it" but sometimes just used to soften a sentence so its not so direct ですよ is harder to explain . it's used when you're really trying to make a point or emphasize something. Sometimes the よ behaves like an exclamation point when you're really trying to get something across , other times its just there to confirm a statement when someone you're talking to is unsure of something.

なにかをかくにんするときに「ですよ？」はつかわれます。 たとえば、りょうりちゅうに「それ、しおですよ？さとうをいれなきゃ！」などとつかいます。 When you want to remind about something, desu yo will be used. For example, when we are cooking, we can use like this "That is salt! You should put sugar" Sorry for the bad English. I hope you will understand^^