So let's start it!!!
Step 1: Modelling
Models are classified by skill( this is used in Revell models) and scale ( from 1:1000 to 1:4),but we will talk about this later.
This is a very amazing hobbie, with no limits for your imagination, kits can be changed as you like or can.
Step 2: Tools
You won't need any kind of special equipment, all I have was bought at a dollar store, except of the glue and the paints.
-X-acto knife or surgical knife (for cutting small edges or repairing)
-Tweezers or reverse tweezers( for little parts)
-Nailfile (treats the plastic as good as Tamiya sandpaper)
-A pencil ( if you're going to cut something it will show you where you must stop)
-Scissors ( to cut decals)
-Glue ( Tamiya Thin Glue is the best, each bottle is 6$ but will last for more than 20 models!)
-Old cloth ( it will be good to dry the decals water, to clean paint brushes and to keep crystal parts safe from scratches)
-Paint brushes (Buy one big, one medium, one small for details and one for making straight lines)
-Tamiya putty or epoxi putty ( useful if you want to repair a broken part or to make a new one)
Step 3: Paint
Best brands are Tamiya, Vallejo, Revell and Humbrol.
On the Internet you'll find conversions charts for them, 'cause in some kits there come specifications for only one brand paint.
Tamiya paint is a little more cheaper than Revell, but Vallejo will be the best option if you want to start modelling with a few dollars in your pocket.
All of this paint is diluted in an special alcohol, but to clean the brushes or to dilute you can use brand thinner or current first aid kit alcohol, which is cheaper and easier to find.
Step 4: The Kits
Best brands for begginers are PM Models, Revell (1:76 kits), Trumpeter and Airfix.
The Scale: for beggining small scale simple models will be the best. A current Sherman tank at 1:72nd will be 8 centimetres long and 2cm wide. With just a few details and a bit of patience you'll obtain a good looking model. If want to build somethin' bigger go to 1:35 scale in armor or 1:48-1:32 (Trumpeter makes awesome models in this scale, they're not so cheap but the finish is spectacular)
PM Models: this is the best brand for begginers, kits have a few parts with not many details, paint schemes are easy and models cost from 1$ to 8$ with a larege amount of nazi secret projects as the Gotha 229 and a Lippisch 13.
Airfix: good kits, easy building but most of the parts are not well made.
Revell: this is the king of small scale, it has 1:76 models which come with a little diorama where you put the vehicle.(http://www.amazon.co.uk/Revell-Panzer-II-Ausf-76/dp/B00155UL6W/ref=sr_1_2?s=kids&ie=UTF8&qid=1350136939&sr=1-2)
Trumpeter: the most 1:32 to 1:24 awesome aircraft kits (big scale not so cheap) http://www.ehobbies.com/tsm3219.html, but 1 72 cold war airplanes like su-17 cost less than 10$, and they are 30cm long, or as the xian jhu, 50 cm long.
Step 5: Skills
To cut a part just use the pliers if it is big, and cut the excess with the knife, and then smooth the edges with the nailfile.
To glue two parts you can hold them with clothespins or with masking tape.
To refill edges or broken parts add some plastic putty, let it dry and cut the excess until the shape you want is made.
Before painting, put the brushes inside a vase of alcohol to clean them.
If the alcohol of a paint bottle has evaporated, add a little and mix with a chopstick or somethinh thinner. You can also use the dust left in the bottles to add some rust or smoke effect to your models.
Also you can download painting patterns or photos to try another markings for your model, or just let your creativity do the job.
If you have any doubt, correction or comentary, don't be shy, tell me!
Tanks for reading!