Speaking of soldiers, they're being one of the hardest parts in modding in bf2, infact even we are scrapped gb soldiers due to problems they caused with kits system.
As for starters, it's much easier to start off with vehicles or static objects, because they have less things to worry about besides actually modelling.
First of all i would recommend you to read
this thread to get overview what's you need to do.
Keep in mind that you gonna need 3ds max
9(not 2008\2009) for export stage, so it's preferable that you start working on this version to avoid problems with compatibility.
Otherwise, if experienced modeller already, short straight-into-modding guide:
1. Model your stuff(+UV, texture)
2.
Set up hierarchy.
3. Export, do basic code for it, test.
4. Make optimizations.
5. Make lods, additional optional geoms(1p and wreck models)