Sound monitor setup

you should not hook them up directly to the focusrite because the focusrite puts out line levels and if your speakers have only wire connections then they are not line level, they will need an amplifier between them and the focusrite. 

for surround type setup you'd probably want to get a home theater type amp (or receiver/amp), then you'd take the RCA outputs to the receiver and the speakers hooked up to the receiver outputs.

however I want to warn you against some things you're going to be faced with in doing this:

1) just because you hook up 4 speakers does not mean that the soundcard is putting surround output.  the receiver might be decoding that for you, but you also have to have surround source.  what are you planning to listen to in surround on your DAW?  if DVD movies, ok, this would probably work because the decoder is in the DVD player, if music - that's not going to work unless you have a music player that will simullate surround for you (actually my home theater type receiver does similuation, too, if that's what you're looking for).  but that's simulation, not real surround.

2)  if you're planning on trying to create surround mixes from your DAW then you have the wrong software.  MC will not do surround.  you need X1 producer for that (not even Essentials or Studio - you need the top dawg producer version)

3) receivers and any home theater type amps will color your sound and you will have problems getting good mixes which translate well to other systems.  receivers are designed to be colored so that you get the best enjoyment out of your living room when you are playing that concerto or the latest action or science fiction movie.  but you don't want added color on your speakers when you're trying to mix a song, you want as flat as possible so that it will work on other systems without you losing low end or without you scooping out the mids because you hear mid heavy mix on the home theater amp/speakers.

The interface will do you well, but you really want to start to investigate in the purchase of a set of decent near field monitors. When mixing your music, you really want to hear your music uncolored so that your levels are represented accurately over the frequency spectrum. You don't want to ( mistakenly ) hype up or lower certain frequencies  due to the non linear nature of your choice of speakers.  Typically, stereo speakers will do this and surround sound speakers are usually even worse.

The wires coming out of the speakers are just the "raw" wire.

to me, this implies it's not a line level speaker input and therefore would NOT be able to hook up directly to the focusrite.

if it's "just raw wire" then he's just got speaker wire connected to the speakers, i.e. home stereo speakers at (probably) 4 or 8 ohm.

There are "mixing" headphones IIRC..... but they are more expensive than the cheaper studio monitors. 

I have a $30 pair of Yamaha headphones..... el-cheapo's .....and I will use them to work on music from time to time when the family is home and trying to work  or sleep in the adjoining rooms. 

Use what you have until you can afford to get some decent monitors.