A lot has to be said for going with whats available like N & HO as the market for these scales is overpowering. Check up on www.walthers.com
for what you might like to start with
cheers
Shamus

Welcome to the ranks of Model railroading. The first thing I reccomend you do is find your self a good hobby shop. They will prove invaluble in getting you what you need, and ordering it if it is not in stock. A hobby shop also has the advantage of allowing you to preview what you are looking at before you buy, so you can be sure wheather or not you want it before you purchase it.

Here is a list of 4 scales suitable for beginning modelers, as well as their pros and cons.

N-Scale. The second smallest operating model railroad scale. (The smallest is Z scale).
Pros:
N-Scale modelers have a decent variety of high quality locomotives and rolling stock to choose from. The majority made by Kato, Atlas, and Micro-Trains. N-Scale by virtue of its smallness in most instances is ready to run out of the box, or after basic assembly of a few parts. Decent selection of locomotives and rolling stock to choose from, as well as a large number of accessories avialable for it as well. Its small size allows operations in a very compact environment. (As little as 2X4 feet) or allows a high track to scenery ratio if one builds a basement filler in this scale.

Cons:
Track must be laid with utmost precision. Due to its small size, even the smallist bump or jog in the track is eneugh to derail a train. Track also must be kept immaculate to ensure trouple free running. Details are small and hard to see. Also easily Broken.

Ho Scale. The most popular model railroading schale.

Pros:
Most common and supported model rairlaod scale around. Lots quailty equipment now avialable as "Ready to Run" meaning operationg of equipment can be made in a few minuts after opening the box and making a few final adjustments. (No matter how precice assembly is at the factory. Final adjustments have to be made at your layout and made periodicly after use of equipment has begun) The number of products from which to choose is overwealming. HO scale componets can be had in many places. Nearly all eras of railroading supplied in HO scale. A good model railroad can be had in a moderatly sized space. (4X6 and 4X8 feet common)If building a basment filling railroad. A good amount of operating possibilties and scenery can be created with good balance.

Cons.
Alot of "Junk" is avialable in this scale often requiring more than the initial investment of the car to bring to proper operating standards. The number of options available can often become confusing. Details are on the small side and can easily be broken of not careful.

S Scale. This is known as the "Maveric" scale due to its relative obscurity.

Pros:

Often in the "just right" catagary for modelers trying to find a balance between O scale which they find to big for their tastes and HO scale which they find to small. Details have a decent amount of "heft" to them and are not so easily broken when bumped or grazed. A myriad of accessories are avialable from other modeling sectors that can be used to support this scale. Scale takes similar space requirments as HO so Can be run in nearly the same amount of space

Cons:

Not much is offered in this scale. At last count only three comercial manufacturors in this scale. Often compromise is neccissary to achieve desired results or must scratchbuild to get what you want. Sometimes you must scratchbuild anyway. If kits are avaialbe and not from the main thee comerical manufacurors they are often of limited production, and take considerable skill. Sometimes the Toy Train (American Flyer is S Scale) market must be raided so as to get something to base a model on. While S scale can fit in the same space as HO. Is some what cramped doing so.

O scale. The King of Scales.

Pros:
Large size makes working in this scale comparitivly easy. Details large eneugh to see and handle confortably. Details are large engugh to handle moderate rough handling. A decent variety of models are avialable in this scale.

Cons:
Large size also means needs lots of room to operate. Most "small" O scale layouts take up about a minium of 10 X12 feet. If its a basment filler it might only make "Medium size" Two competing methods of control make choosing and selecting equipment tricky. Most kits require some model building skill to assemble.

This is what I have for you to consider for now. If you have any more questions please feel free to ask. I have broght many a new model railroader into the fold and would glad to help you get started.

sincely