If you are making a mod for the first time, I have some suggestions that might help you. I know these may sound obvious, and you probably know them already, but following them makes you work in a more efficient and focused manner:

1// Plan your mod. This means working out all the sides, units and buildings. Also, which logic you intend to make use of, and which factions will have which features. Basic tech trees and some background info on the mod should also be put down.
This allows you to stick to a defined route, meaning that you are less likely to get sidetracked on a minor part of the mod or get hung up. It also allows you to guage your progress properly as you work.

2// Know your limits. You know yourself better than anyone, so don't set yourself tasks that are beyond your reach. For example if you cannot make voxels, and are having trouble learning, then try and make use of the public assets if at all possible. Resizing and recolouring public assets (assuming you have permission to do so) is much more practical than asking for voxellers to make specific work. This also applies to other aspects of the mod, such as coding and buildings.
Again, this might be obvious, but having a huge number of units that require lots of specialised work means that they probably will not get realised unless you can do the work yourself.

3// Be realistic. There is no point in designing a mod with 200 new units and 80 new buildings as well as new terrain, unless you are a modding machine. Two sides with 20 well thought out units is not only more likely to get made, but will also force you to define each unit properly.

4// Ask for help. Most ppl get stuck at some point, and ask for help. Asking for help is not the same as asking for somebody else to do the work for you though, and this is something many do not seem to realise. If you need a specific voxel, or a particular type of weapon, explain everything in as much detail as possible, with examples or pictures where appropriate. Ppl are more likely to help out that way than if they see it as too much work for somebody who won't learn on their own.
Also, the recruitment of team falls under this section too. Unless you have got reliable and productive ppl helping you out, plan for the worst-case scenario; modding the whole thing yourself. By all means have things that "would be nice" to add, but make sure that their absence doesn't screw up the mod totally.

5// Report progress. If you want to get ppl enthused about your mod, you'll need to show off proper progress at intervals. Unskinned WIP models and huge screenies with one public asset in the corner will impress nobody. Make sure that you are specific about what you show off, and that you explain it properly. Models/units should be properly finished and the pix should be succinct and of good quality. The quality of what you show ppl, as well as how you present it, goes a long way to conveying your approach to the mod. In many cases, the approach to and progress of a mod are more significant than the storyline!
Having a good profile for your mod means that more ppl would be willing to help should you ever need anything, as well as take you more seriously when you get stuck.