Some things are so obvious it would have been helpful to have had them explained. Maybe with graphics. Before Critter McG was born I washed and folded piles of teeny tiny onesies that he went through so quick I was back to washing and folding sooner than I thought.
The only kind we used for the first three months were the ones that buttoned all the way down. When they're really tiny babies freak out if anything goes over their heads. Plus, you're still learning to move him without separating limbs, so a button down onesie can be tucked under the baby and you can roll him gently to get the other arm in. Works beautifully.
Until he learns to roll over. Then forget anything that has more than the three necessary buttons on the bottom. Dressing should be as quick as possible and if you can do it with the baby on your lap, even upside down, all the better.