The easiest way to get started in model railroading is to buy a set. It isn't necessarily the only or the best way, but the easiest. When choosing your first electric train set there are many factors to consider: size, quality, and budget to name a few.
Before going out to buy a set, you need to think about how much space you can dedicate to your new hobby. Is your new set going to be pulled out occasionally? Laid out on a plywood sheet? Or do you have a man cave you can turn into Penn Station?
Full Size Bed Rail
Trains some in a wide variety of sizes called scales. The most common scales are O, HO and N Scale. Obviously, the larger the scale, the more room you will need to dedicate.
O Scale is the largest popular scale it varies from 1:48 in the US to 1:43.5 in the UK. O scale trains (or Trains O Scale) have the most detail and are incredibly popular with serious enthusiasts (with serious space to dedicate).
HO Scale or HO trains (not to be confused with Snoop Doggy Dogg) is by for the most popular scale. HO Scale is Half O Scale (1:87) hence, HO Scale. Due to its popularity, HO model train accessories and sets are easy to find and widespread availability. HO Scale offers lower space requirements while still affording a good amount of detail.
N Scale is the smallest popular scale at 1:148 (but far from the smallest commercially available scale). N Scale trains have the lowest space requirements and are great for older children since they offer more flexibility than a boring oval track tucked under their bed. However, the reduced space is at the expense of detail.
You next need to set a budget for your new railroad. You can spend as much or as little as you want, but haphazardly stumbling into a hobby store and buying bits and pieces can get very expensive, very fast. The best thing to do is to have a focus. Choose a railway to start with. Most people choose lines they remember as a kid; Lines such as Santa Fe, Canadian National, and Union Pacific to name a few. Having a focus helps with planning and budgeting.
The next consideration is track. Make sure you are using the correct gauge! Gauge is the size of the track (the distance between rails) whereas Scale refers to the size of the model train. O Scale will run on a larger gauge of track than N or HO scale.
Choose track that has an integrated roadbed. The roadbed is the raised bed the track lays on. When you go to real railroad tracks, you usually see the tracks on a raised bed of gravel. This is the roadbed. Having a roadbed makes assembly and disassembly much easier and efficient. If you are just getting started, you probably won't be laying out a full-scale railroad just yet.
A rule of thumb is always buy the same brand of integrated track - brands aren't interchangeable, they have proprietary bed heights and connecting mechanisms.
Hopefully, this is enough useful information to help you make a sound decision and get you off the platform and onto a scale train. Your journey awaits!