Modeling tutorials hosted in PMC Editing Wiki, you can rest assured that links for these will always be active.

Gizmo Mapping by Ebud

Spherical Gizmo Mapping by Remcen

Correct Texture by Ian Malcolm

Smooth and Sharp Edges by Ian Malcolm

Creating Simple Building by Ian Malcolm

Importing 3DS model to O2 by Ian Malcolm

• Getting Started by Brsseb.

Oxygen 2 tutorial. Helps you to setup O2.

• Lesson 1: Creating your first addon by Brsseb.

Creating your first addon.

• Lesson 2: Creating your first car by Brsseb.

Creating your first car

• Lesson 3: Creating your first Weapon by Brsseb.

Creating your first Weapon

• Lesson 4: Creating your first Helicopter by Brsseb.

Creating your first Helicopter

• Lesson 5: Creating your first Gunboat by Brsseb.

Creating your first Gunboat

• Lesson 6: Creating your first Airplane by Brsseb.

Creating your first Airplane

• Lesson 7: Creating your first ARMED Airplane by Brsseb.

Creating your first ARMED Airplane

• Lesson 8: Creating your first Building by Brsseb.

Creating your first Building

• Lesson 9: Custom Object Animations by Brsseb.

Custom Object Animations

Animations Intro

Pseudo Multiple Aircraft Weapons effects by Col. Klink.

Animated Undercarriage Gear and Gear Up warning sound by Col. Klink.

Animated Navigation Lights by Col. Klink.

Animated Canopies by Col. Klink.

Animated Aircraft Exhausts by Col. Klink.

Texture Changing by Fab.

Advanced Texturing by Fab.

Smooth/Sharp Edges

Modeling the Piper Cheyenne executive aircraft by Col. Klink.

Damaged Tank by Fab.

Intro by Fab.

Intro by Fab.

Here is some additional tutorials found on the net. Texturing tutorials (nothing to do with O2 or OFP stuff).

http://www.sourceblog.net/page.php?file=/tuts/skin/skin

http://www.planetquake.com/polycount/resources/general/skinning.shtml

http://www.planetquake.com/polycount/resources/general/video_tutorials/video-tut-list.shtml

http://www.secondreality.ch/tutorials/materials/wornmetal/wornmetal.html

http://st.burst.cc/tutorials.htm

http://cdg.csnation.net/

http://redhammerstudios.com/DAR/index.php

UVW Mapping in 3DS Max
http://waylon-art.com/uvw_tutorial/uvwtut_01.html

Camouflage sites

http://henrikc.dk/camouflage/index.asp

http://www.aos-blaesius.de/camouflage-nof/camouflage-nof.html