Zuiko lenses

[hydro psyche]

Hello all

First, let me give you all my photography background(which isn't much).

I recently purchased an Olympus e510 in hopes of expanding my photo taking capabilities. My old camera was a Pentax Optio W10. This camera suited me since it is waterproof, and I do a LOT of fly fishing all over the east coast. I saw pictures that a friend takes out in the field with his DSLR and I wanted to be able to take pictures of that quality. The Pentax is OK, but doesn't always give me the shots that I want.

So....back to the topic at hand...the Olympus came with two lenses: 14-42mm and a 40-150mm. I've been doing some reading and it seems that a 50mm lens is recommended for landscape shots. I'll primarily be taking landscapes, as well as pictures of insects, birds, flowers, and anything else I might find while out on the river.

Can I use the 14-40mm lens for landscapes or should I purchase a 50mm fixed lens? Can someone explain the difference, if any, between the 14-40 and 50mm fixed lens?

Please keep in mind that I'm very much a beginner, so the more information, the better.

Thanks in advance.