My friend and I are traveling to NYC in April. Staying mid-upper west. What would be some good places to go for nitelife, safe for females traveling alone & what should we wear to not look too touristy?

As a lifelong New Yorker and former Upper West Sider - what type of nightlife do you mean! NY has theatre (both B'way and off B'way), comedy clubs, dance clubs, great restaurants.
Don't worry about looking like tourists - you are, you know! Some of us New Yorker's would say to war black. Mid-April could be full blown springtime, or still could be a little cool. Have fun.

Eaxactly what you wear will obviously depend on where you're going - but black is always safest and New Yorkers in general - assuming you're 25+ - go for sophisticated but not "dressy". I would assume mid-April will still be fairly cold at night.

thx for the info - i am from nyc - lived on west end ave from '57-'65. live in nh. we are looking to go to clubs/bars safe for females traveling alone

Well, there are many places on the UWS that cater to a pretty young crowd -- I don't think you would enjoy any of the "clubs" in the area. My suggestion would be to have drinks at, say, Jean-Luc on Columbus and 83rd or Nice Matin (drinks/dinner) which is located at 79th and Amsterdam. You will be safe pretty much everywhere on the UWS.