November 23rd, 2014, 14:15
How much spare time do you have? You're going to need plenty plus a fair bit of patience!
Do you have FSX Deluxe or FSX Gold Edition? The software development kit (SDK) is supplied with these and includes the plugin for Gmax to export models to FSX. Gmax is a free download and is wonderfully capable, but takes a lot of learning - as does the whole modelling process. FSDS from Abacus Software is an alternative for not too much money but don't spend anything more than that: there is another modelling tool used by some (including me) known as 3ds Max and it is appallingly expensive. Blender is another free alternative which is becoming used for FSX by a few since the tools were developed recently.
For everything else, unless you already have some expensive software, stay cheap....