Milky Way, view outward or inward?
An image of the whole sky (360 degrees) centred on Sagittarius and rotated so the galaxy is in the middle:



This image from the "2MASS infrared survey" actually uses infra-red light, as it penetrates the interstellar dust better than visible light. It shows that any apparent curvature is an illusion. The milky way goes straight across the sky.

It also shows that when we look towards Sagittarius we look towards the galactic centre, and when we look away from it (towards Auriga) we are looking through to stars in the outer spiral arms. The night side of the Earth faces the galactic centre during July, and faces outwards in January. 

Also visible in the image are the two Magellanic clouds (small but nearby galaxies outside the milky way), the clear bulge around the centre of the galaxy and the dark bands of dust along the milky way. The central bulge is much brighter in infrared than the spiral arms. Using infrared makes these features more visible.