There is a list of trusted dealers on the site so you will want to look at that list and figure out which dealer you want to go with. My experience was good - I think the main thing to start is having good communication with your dealer. If he is responding to your questions quickly he is probably a good person to deal with. Also look at the forum to see what other opinions are of a dealer. Since you have already chosen a watch your next step is to get the QC (quality control) pictures as there are a few things you may want to check there. Since you are new to reps you may want to look into posting some of the QC pictures on the site to get the opinion of others on the quality of the item. If there are any problems you can always ask for another one at this stage. Beyond that you are good to go.
Once you get it, if it looks great on your wrist, and you decide you want to keep it, then the next thing may be to look into getting the watch serviced. They can take it apart and clean it up nicely as part of servicing; if you can find someone in your area even better. This can sometimes be pricey so you will hear different opinions on servicing vs. replacing any components if they fail.
I am new to this as well but that's what I have learned over the past few days