Just to add a bit... Assuming that you're starting from S13. Starting with 4-lug S14 is different.

Rear: S14 rear or Z32 NA hubs/bearings, and you'll need S14 5-lug rotors. The hubs are pressed into the bearings, and the bearings simply bolt it with 4 bolts.
Front: Option 1: Simply bolt on Attain/Peak Performance 5-lug conversion hubs to your S13 spindles. Option 2: Get S14 SE 5-lug front spindles with 5-lug hubs/bearings. Press in S14 ball joints to the S13 control arms. Holes in the spindles for the strut bolts are larger on S14, so either get some spacers/sleeves or drill out the holes on your S13 struts and use S14 bolts. Option 2a. All S14 front spindles are the same. So you could get a set of new 5-lug hubs (just the hubs) from Nissan, and bolt them on to spindles from an S14 4-lug. This option is good if you find a set of S14 4-lug spindles for cheap (free) and want new bearings/hubs instead of used stuff. Add 5-lug rotors to Options 1, 2, and 2a.