GUEST,repairer -
Use standard 5-string banjo strings. The 5th string goes down a brass tube and emerges usually next to the bottom left tuner (as seen from front of banjo). The 5th string runs through a slot in a small individual "nut" at the 5th fret.
As for the rest of the strings, run them from the attachment at the tailpiece (I can't see tailpiece clearly on full banjo photo, usually there is a slot in the tailpiece which you thread the strings under, so they are held tighter to the bridge). When they cross over the nut, it is usually pretty obvious which tuners they match up to.
When placing the bridge, you need to measure the distance from the nut to fret 12, then place the bridge at the same distance the other side of 12th fret. When fretted at 12thfret, the note should be exactly an octave higher tan the unfretted string. If not, either the positioning is incorrect, or the neck angle may be too high, and you are stretching the string too far.
Quack!
Geoff the Duck.