You can post as many stories as you want, although I wouldn't because one good post a day is worth 100 shit posts a day and people will get sick of your constant posting and mute you.

You can also vote as much as you want in a day but we all have voting power and to keep your voting power at 100 it's advisable to vote no more then 40 times a day, otherwise your vote will be basically worthless.

The $ below your posts is showing you the $ value your post is making in steem, steem power and steem dollars.
Each post has a 7 day period before payout is made.

Hope this helps anymore questions just ask.