In a dynasty your intital draft is going to help (or haunt) you for at least 3 or 4 years.
You definately want to acquire youth, but remember you want to be productive this year as well. Westbrook, TO, etc shouldn't be overlooked just because they are veteran players. Don't overlook talent because they aren't 24 years old.
Like dream said above....if you are the fence about a certain couple of players at your pick, go with the younger player. Chances are he'll have more time left in the NFL, and thus give you more production as a keeper.
Remember...in most dynasties the only players you will be able to acquire year to year are new rookies, so make sure you do your research now so you aren't dealing with major issues in only a year or two.
And you can always get help choosing in your draft right here