My Inspirion 530S

Hello...I'm new to this so forgive my ignorance!  I have two issues that I hope someone out there can help me with. 

First: I leave my computer on all the time...it goes to a screen saver of photos I have uploaded.  Occasionally, I will find that the monitor is completely black though the light is still on the harddrive.  I move the mouse and click the keyboard to "wake" it up, but this doesn't work.  Nothing I do will turn the monitor back on.  I know it's not a good idea, but the only thing that I have found that works is shutting off the power strip, waiting, then turning it back on.  Any ideas??

Second: My USB Dell mouse is tempermental.  Sometimes it works okay but most of the time the light turns off and on (the red light underneath it) and the mouse freezes.  I have to keep moving it and then it finally moves, only to freeze again.  It makes a "bonging" sound when it doesn't move for me.  It is very frustrating and I don't know what to do.  Any ideas here ?

Thanks to anyone for their help...