S.J.
Honestly, I would take a week (or as long as you can) off of work. When we did our first (2 years old), it took us just a few days, but we were very consistent and stayed home the entire time (Christmas vacation). He was also our easy kid!
And to start, you just set his little butt on the potty seat and tell him this is where he goes potty now. Let him sit there as long as he likes, but don't make him sit there if he doesn't want to. Then just keep checking on him every 20-30 minutes to see if he has to potty.
We gave rewards for going, just your basic little chocolate chip or small candy. We made it super exciting and never punished for any mistakes. We put him in underwear full time. I honestly don't even think we had one accident.
We also had a potty chart with stickers. We just made it ourselves, you can google ideas. One Step Ahead website has some really innovative ideas for training.
Tell the day care you are starting to train. They should assist you in also training him while he is in their care.
And do not get discouraged if he doesn't get it during your week off of work. I know plenty of three year olds who just aren't ready. He will get there, I promise. I always tell discouraged moms I promise he won't be wearing diapers in his teens, so stop worrying. =)
Good luck