If your only doing veg for a month I wouldn't recommend even starting nutes until you start flowering!
And when you are ready to start using nutes PLEASE PLEASE PLEASE PLEASE PLEASE start off with a VERY VERY VERY VERY WEAK DOSE OF THEM! I'd recommend 1/4 strength of the recommendation for whatever you using.
If you don't have a tds/ppm meter then you need to start very weak, and I'd say use the following schedule: nutes:water:water:nutes: Possibly another water in between depending on how your plants react.
Slowly increase the nute dosage. If they start showing a little nute burn flush the plants and lay off the nutes for a few feedings.
If the nute burn is very minor (like the picture above) the plants will actually be fine. I've let mine through worse nute burn and they turned out ok =p