polish them with a medium compound if there bad or some finishing polish if there not too bad then seal them and wax them twice which will ensure they'll stay in good condish, keep it up aswell, people tend to only do this once then forget about it and wonder why there rims go back to the state they were in before. top up the sealant and wax once a month if possible or as frequently as you can. wheels obviously see alot of crap being so close to the road and they also have to deal with corrosive break dust so keeping ontop is key.
hope this helps.