Router bits

I have my template cut out of 1/4 ply. I decided to go to 1/8 baltic birch #1 because it is much lighter and #2 because I found some locally.
My only exposure to routers is using them to cut laminates off table edges.
What kind of bit do I need to cut the side walls? I have figured out that I need a pattern bit. Is it better to have the bearing on top or on bottom? If I'm using it to cut the pattern, should I go with a wide cut or a narrow one? Does it matter? Should I use a bushing instead?
My only exposure to routers is using them to cut laminates off table edges.
What kind of bit do I need to cut the side walls? I have figured out that I need a pattern bit. Is it better to have the bearing on top or on bottom? If I'm using it to cut the pattern, should I go with a wide cut or a narrow one? Does it matter? Should I use a bushing instead?