Need help with some style advice. - by: Silo399

I'm looking to buy some dress shirts as I have none whatsoever but before i do I need 3 questions answered. Thanks in advance.
1. Are long sleeve or short sleeve in for summer style/comfortability?
2. What tone of colors are in... darks(navy/maroon) or Brights(Whites/Yellows/Pinks).
3.Can button ups look good with jeans or is it better to stick to chinos?