How do I know if he or she is the one?  Well, first you need to define what "the one" is.  Each person goes on a search for a mate for different reasons, for different types of relationships.  You may be looking for a life partner or spouse.  You may be looking for a purely sexual relationship (either long-term or one-night stand).  You may only be looking for friends or other companionship.  Whatever you're looking for, and whatever stage of the relationship you currently find yourself, you should ask yourself some basic questions before moving on to the next phase.  Here are some basic questions to ask yourself before making any further decisions.

1.  Looking for spouse or life partner (no children involved)

• Can I see myself spending the rest of my life with this person? 
• Do they have any beliefs or views that are fundamentally opposed to my own?
• Do they have any habits/eccentricities that I don't think I could deal with on a regular basis?
• Can we communicate clearly with each other, about important things, and about banal things too?

2.  Looking for spouse or life partner (children are involved)

• What role do I expect him/her to play regarding my children (and vice versa)?
• Will this person be able to assume that role, and respect my boundaries and wishes?
• Will my children be able to accept me starting a new relationship?

3.  Looking for sexual relationship (in Talking Phase)

• Do I trust this person enough to arrange to meet them?
• Have we established a good enough rapport to ensure that our meeting will not be uncomfortable and awkward?
• Is there a safe, public place to meet?

4.  Looking for a sexual relationship (in Meeting Phase)

• Do I feel comfortable moving to a more physical relationship at this point?
• Will I regret anything I have done the night before the following morning?

5.  Looking for Friendship or other companionship

• Do I trust this person enough to tell them sensitive things about myself?
• Can I feel comfortable knowing that my "secrets" are safe with them?

As always, this is not a comprehensive list, but these are some good guidelines to follow when evaluating a relationship.  The best advice I can give you, in general, however, is to trust your instincts, or go with your gut.  Your conscience is usually a pretty good guide in almost every situation.  So, don't ignore what you're gut is telling you, and make decisions that you feel confident that you won't regret in the morning, or 20 years from now. 

Happy Hunting! 

Regards,

Will