Make sure you build your smelters as close to the mine as possible, and align the docks with the mine dock. (Smelters should be no further then 3 squares from mines). This shortens the round trip for Cargo Trucks. Additionally, have at least TWO smelters/mine. Also, have no more then 2 cargo trucks/smelter.
Make sure you get on the Tripple Commons/Rares that exist on the map. There should be 2 tripple commons, and 1 tripple rare.
Don't worry about using Geothermal. If you have extra resources, build Solar Power instead. Otherwise, just build toks as needed and just keep them repaired. As attacks will come in from the West as well, and waste these geothermal power plants, its just easier to defend a more centralized location.
For EMP missiles: Build an observatory, and cover your base with Meteor Defenses. These will take care of *most* of the EMP missiles Plymouth will shoot at you.
*Note the range of a Meteor Defence is about the width of a screen, in a circular area.
Use primairly vehicles, and place a few guardposts at the AI's attack routes. This provides double the portection.
Have at least 2-3 Vehicle factories constantly pumping out tanks.
For Morale: Get an Agridome up ASAP. You don't want to starve. After that, get a Nursery. (For some reason, they don't give you one on this mission). Then build enough Medical Centers and Residences as you need to keep demand under 100%. Build about 2 - 3 extra agridomes after this. That will get your food up. Plymouth does hound you, but the attacks are beatable so long as you get vehicles to back yourself up.
Note* DIRTS reduce EMP time for buildings, as well as prevents damage from weapons/disasters. This makes them EXTREMELY valuable. Use them!
If you have reserched Recreation Facilities and Metal Reclamnation, you must have both Recreational Facilities and a GORF, as these affect morale. (Recreation Facilities have a demand, a GORF does not).
For tanks: Concentrate on produceing mainly Thor/EMP/Acid combinations. Whatch that your acids don't shoot your own vehicles (though against an AI this shouldn't be a problem). Have a mix of Tigers/Panthers/Lynx. Panthers/Lynx are especially valuable early on while you try to get your ore going.
Don't worry about mission objectives right at the start. Concentrate on stableizeing morale and gathering more ore. After that, get defenses up asap. Once your base is secure, then work on the objectives.
You get a lot of time to complete this mission, so don't get in a panic.