He's truely ready when he's waking up in the morning or from naps dry. That is the perfect time to take him immediately to the potty without pressure.And if he awoke dry it's obvious he will need to go. If he's not waking up dry he's probaly not quite ready physically with the bladder but you can practice using the potty throughout the day occasionally.
After he has mastered that start working in more and more potty breaks throughout the day. Until he's mastered potty training.
When he's no longer having accidents put underpants on him.
If he has a accident in his underpants don't rush to change him let him experiance the uncomfortableness and then let him be in charge of changing and cleaning up. Not as punishment but as responsibility. Of course you will be needed to guide him or help but it should be his job. That way having accidents doesn't become a game or attention grabber because he will learn it's more work and not fun.
Pull-ups are a waste of money and make changing a dirty diaper harder. They are to absorbant and make it just to comfortable.
Just don't force it. Many many parents try potty training a few different times before it works.
I try and stay away from bribes as well then it turns into a power struggle because they know you want it so bad yet they have 100% control over this.
Make it fun. Be silly and announce whenever you or if you are married your husband need to go. Leave the door open and let him be a part of your bathroom time. Make a big deal that you have to go and show him how and then act like it's super fun to wash your hands when your done and let him think this is really cool. My daughter and I use to race to the bathroom to see who could get there first worked like a charm.
Good luck!