[kooldraco]

to check if it's stranded or solid simply strip a little bit of the cable and take a look at the bare wire, if it has a bunch of little wires instead of a solid one then you got stranded, if you buy them new at the store then it should say on the label. insulated means that there is a rubber coatting all around the wire (not the bare wire exposed).
cat5 utp cable does say it's 24awg, although I never done it before so i don't know what the results are, I don't think using networking twisted pair cable is a good idea. i think you're better off buying regular solid core and insulated hookup wire, it's really not that expensive and you don't need that much.