It's really hard to say. Programs are like traditional media. Try both and see which one you like better. Otherwise just stick to photoshop. Do what works.
I do a lot of design, for menus, and fliers, and mainly print documents. For the majority of these projects, I just use Photoshop. So I literally create an 8.5"x11" canvas and create the flier on there. Is this correct? Or should I use a program like publisher? Please give a novice designer some advice. Thank you.