Need advice from the pros

Looks to me like you've made a good start with your scenery and track, msp.

I'm partial to Woodland Scenics materials. The more you work with it, the better you will develop a good sense of color and texture. I find working on scenery to be one of the most enjoyable things to do in the hobby. Arnold

Adding some flocking ("grass") will greatly improve your base paint layer. Good start!

Also look into static grass

I think the number one thing you can do is paint the sides of the rail.  Real railroad tracks are not shiny, yet lots of layouts with otherwise great scenery are spoiled by shiny toy track.  I used Rail Brown with a little bit of black added.  It was painted by hand, with a small brush.  Doing a little bit every day will get the job done!

Yes I have done some static grass in the past will do that with some other grasses and shrubs.  I think I need to add more plaster to the bottom can still see the cloth.  the plaster cloth i used was a little short on the plaster.  

Painting the rails...looks great but probably more than I want to take on.  

Looks like you're off to a good start. Paint the rails, spray is faster, but a wash of acrylics applied with a brush will work just as well. Wipe down the top of the rails as you go.

Finish the ballast.

Start adding ground covers, trees, scrub brush, rocks, general track side junk, etc.

Woodland Scenics makes a good selection of products.

Easy to transform a bare plywood base to something much better.

Plaster cloth and paper make for easy terrain too....

Don't stress over this stuff......This is the fun part of layout building.

Bob

Great photos, and yes, keep the top of those rails clean! even if you don't paint them, other types of overspray, ballast glue, matte medium, whatever- can dry on them.