The system has many apps built on top of it to assist you in that regard. I suggest you use the add on for your browser called steemit more info. Other than that click on the menu on the right and open steemit app center. There you will find many additional tools to use on steemit.

You don't lose your steempower value when you vote, your "vesting power" goes down slightly, with one of the several addons for the browser or the alternate user interfaces for steemit, you can see your vesting power, and everyone else's. If you vote all day, eventually it isn't worth anything, but you aren't losing your invested steempower, just your daily vesting power per vote. As you attain higher levels the normal steemit interface allows for more options to change vesting power so you can vote more and each vote is worth less....which is very helpful for those who have high vesting power and don't want to spend it all on a few upvotes.

It is somewhat complex, but less complex as you discover the tools and learn more about the voting system.