Track Joining and Placement

Basics of joining sections of track, and placing them, roadbed.

Rail Joiners, Soldering; nailing, gluing; plastic, wood, cork & foam. Whats the point of each.

When placing your track, you've got TONS of options. From ways to connect sections of track, to ways to secure them, to the roadbed.

Rail joiners & soldering each serve the same purpose. Rail joiners are the easiest way to accomplish connecting track sections. However, there's a minor downside, contact is not always perfect. If the joiners are loose, they can loose contact, thus creating a dead spot in your track. Also, when gluing ballast down, if glue enters the joiner, it'll do the same.
Soldering can keep this from happening. Soldering takes a bit of learning, I'd suggest practicing on some scrap track sections first. The major problems her are the hot soldering iron, and the possibility to melt the plastic ties. Heat sinks and help this.

Often, I'll combine both. Using Micro Engineering rail joiners on Micro Engineering rail is suitable, but I'll solder most joints after to decrease movement, and increase electrical conductivity.

Securing your track to the scenery is another fun topic.

You can nail the track to the roadbed, & sub-base, however this does not work so well if you do not use plywood, and cork roadbed. Nailing options include the small hole directly center in the section of track, or drill out a few spikes, and use rail spikes.
Gluing is coming into favor with more modelers now. Gluing allows you to avoid tenting the rails, or warping the ties. It also works best when using foam roadbed, or foam sub-base. The options for gluing are endless, however, most people report good results from wood glue, Elmer's Glue All, or adhesive caulking. I prefer the caulking as its the easiest to remove the track from, if I change my mind.

Roadbed brings up an interesting topic. Options include cork, foam, & wood, plus the plastic of track with pre-installed road bed.

Cork, common, oldie, but goodie. Great noise canceling properties, cheap, and effective. Can be used with glue, or nails. However, it has been reported that it can dry out over time, and become brittle.
Foam. There's two options here. Using the soft spongy foam that Woodland Scenics sells, or insulating foam board. The advantage of the WS product is that it's soft enough to cushion the rail, and deaden most sound. Foam insulating board works wonders, and can be shaped to do the sub-roadbed and roadbed, plus surrounding scenery all at the same time. Track then can be glued directly to the top.
Wood (or Homasote). In years long passed there was sectional wood roadbed available. However, now you can just simply used plywood under it, or just attach it sans roadbed to the plywood base.
Plastic roadbed comes on some sectional track, and can be used effectively, however does not have the sound deadening ability of the cork or foam.

Hopefully this helps you understand some of the common methods and products used to secure track to your train layout!