I have 2 models that I want to import into Fallout 3 as mods but I have no experience with using TGA or obj. files. Anyone know how?

Blender version 2.49b has tools which allow you to import .OBJ files and export .NIF files, the file format that Fallout 3/NV uses for its meshes. Links to blender 2.49b, the niftools, and python required as well as install instructions can be found here:
http://niftools.sourceforge.net/wiki/Blender

You will also need nifskope to clean up the .NIF files found here:
http://niftools.sourceforge.net/wiki/NifSkope

From there you would want to rig your 3d models onto the humanoid skeleton used in fallout 3. There are few tutorials about this:
http://wiki.tesnexus.com/index.php/Creating_an_armour_for_Fallout._Part_1

WarfareChild53 wrote:

I have 2 models that I want to import into Fallout 3 as mods but I have no experience with using TGA or obj. files. Anyone know how?

Do what @clanky4 suggest.

As for tga files they have to be convert to dds. You can use GIMP + dds plugin.