Being relatively new to video game design doesn't mean that I haven't picked up a thing or two in the last year. One of the things that people sometimes forget to mention is what a brutal field it is. From the long hours to the highs and lows you will experience, there is little that can prepare you for developing video games. The actual design of video games is a very organic process with games changing and evolving through the different cycles of development from concept to the playable product at the end (which is sometimes very different than that original idea that was in your head).
One of the things that I've learned is that it is really important to create a milestone type system to force yourself to stay on task and on schedule. Understanding that everything will likely take about twice as long to do as you initially think is a good starting point. Overestimate everything, then at worst you have extra time to test and do fine tuning (never a bad thing, although unless you are seasoned veterans I doubt that extra time will be a big issue!).
The last thing I will talk about now is the initial planning, where you are drawing concepts and writing up game docs etc. (and if you aren't doing those things then . . . DO THEM!). Spend a little more time here, and make sure that you've got as much of the game clearly worked out and by this I mean detailed, thorough and step by step understanding of how the game will work. All the people on the project need to understand all of what is happening and what the feel/style/design of the game is (or will be) and be on the same page. For example if you are working on a game with an animal for the protagonist, and the artists are creating them walking on two legs and the programmer is designing them on all fours then there will be some wasted time when those two things meet (not that you will make a mistake like that, but it could happen).
Good Luck (you'll need it, and lend me some while you're at it!)