top = 2 base layers one short sleeved one long sleeved
bottom = lined bike shorts or liners; baggy shorts; loose fitting pants
more top = fleece shirt and or fleece vest; windbreaker with zip off arms

its all about temperature regulation and water (perspiration) management. on 2 recent rides I went through a huge variation of temperatures and changed my layering throughout the day think base/thermal/wind. it takes a while so experiment. lined bike shorts are great even if you only wear them under other stuff like those lightweight convertible pants
http://www.rei.com/product/796167
http://www.rei.com/product/746907

if it's going to be hot like 60+ degrees then you can get by with just a single layer up top but bring another layer with you just in case.