Cat5 phone/data installation

Hey all. My building was completely re-wired with new Cat5 phone line to all 5 units. When I moved in, I ran $14 Home Depot special 4-conductor phone cord over to my desk. Now that I have DSL and want to move the desk I figure I should do it right this time; you know, not twist wires together with duct tape

-Is Cat5 and LAN cord the same stuff with different connectors?
-Do I just use two of the conductors and leave the others unhooked?
-Can I improve the signal by using two conductors for one post, or will I have synch problems with DSL?
-How do I connect wires together without breaking them? Solder? special crimp connectors?

I have about 200' of blue Cat5 that I bought at a yard sale and it has LAN style connectors on it. Do I just cut and go?

Any help you can offer is great since I'm a little bit like a fish with a bicycle here. I'm a contractor and I'm fine with electrical, but phone stuff has always puzzled me.