I have this wireless access point (3com office connect) I am going to run up into the ceiling at my house so I can get a better signal at the other end of the house.

I know it isn't ideal but My setup is such that my modem/router is in my garage and the ceiling access is directly above it so I can run an ethernet cable and power cord through it and along the ceiling to where it needs to go.

My question is this:

The access point will be in the ceiling above the lounge rooms and bedrooms so which way should the aerial point? straight up or should I lie it 90 degrees to the ceiling?

Recommendations please?