How can these textures get fixed? I have a student who is working on a project, but is using other source to complete it. I am not an expert when it comes to blender so I am not sure how to answer his questions. I was wondering if anyone would know some of these answers. I copied his email to me with the images he attached. 

"Alright, so here's the screen shot



The things are tinted blue (fence and roof are odd exceptions) from the blue sunlight. I don't know how to un-tint it. The sun is blue because a blender video said it would make shadows more realistic. That random white line is a plane that somehow got in there and I deleted it after I took the screen shot. I don't know why the house is green-- I'm pretty sure I made it yellow so that's a problem. I think it's green because it's reflecting the grass.

I downloaded a bunch of textures for the wood, garage door, metal, and roof. I also followed a youtube video on how to make grass that was awesome so I think I learned a bunch from that. 

My questions are:
How to make the textures apply properly, edit them, and not be diagonal?
How to prevent structures from reflecting so much of the light around them?

I have a third question as well: Anyway I can connect the gaps between these two planes? I want one of them to be the road."
By UV-unwrapping them correctly.



Without UVmap the textured object appears all made of one color (a sort of average color of the texture)



By unwrapping the geometry in proper way (in this simple case, just a basic unwrap is enough) you'll be able to se the texture cover the plane as expected.

Notice that the Uvmap in the uv/image editor has the two triangles located in a way that reflect the faces topology.



Resetting the UVmap brings all the faces to cover the whole texture..so the triangles are both in the same location, overlapped. So each faces show the same part of the mesh, leading to the behavior you step onto.

Notice how the vertex order of the faces determines an unexpected rotation of the textures on the geometry. This brings a discontinuty in the textures which now don't follow anymore the mesh. Every face has it's own UV.

You have to re-unwrap them.