Slides are best for scanning as theres no orange mask to invert which differs between films, with slides all you have to do is scan them. However having the scanner profiled against an IT8 target will give a much better result because otherwise each scan will be like how each scanner interprets it, when profiled against a target each scanner will in theory give the same result.
More recent negative films such as Kodak Portra 160 and 400 and Kodak Ektar 100 are more optimised for scanning and using software such as Vuescan with film profiles can make negative film scanning much more easy. I would definitely recommend getting Vuescan as well.