I am actually a super moderator for a site called currencyboard.net, I just help out and post as much as possible to keep the content fresh and up to date. I would say it's best to get a moderator a couple of months into your forum, when you establish a little bit of traffic, to help you maintain that traffic.

For me, i'd ask for an application on the forum where people can fill out if they want to apply for moderator. I ask what are their experiences on forum, if they been a moderator before. Also if they know basic HTML sites. I also added like, "As a moderator, what things will do you as a moderator to help out the forum?" I also recommend you to find people who has a lot of post and active on your forum. I had a few moderators who was inactive, so make sure you check who will be the best for your forum.

Generally, what we find is that the forum is advertised stating that the first few will become moderators. And the only reason the first few join is to gain a moderator status. They might not really be dedicated on being a moderator.

Once many members join, seeing them all, it could be decided who is capable. Moreover, moderators are needed only when there is a huge task at hand to handle, i.e. the number of members being above 100 etc.

But if you have a few of your friends, you could always appoint them as moderators initially. But appointing any stranger right away might not be a good idea.

I don't think it's necessary to look for a moderator if you have fewer than 100 members.
Also, I wouldn't look for outside help, but rather you can offer to promote one of your more active or helpful members. Someone once said to me that you shouldn't advertise that you are looking for a moderator on your website, as then the people who apply are not the people who will be committed in the long-run. As the administrator of the forum, you should be extremely active, and therefore you should be able to properly gauge who are the 'better' members of your forum and who you can likely trust.

What I would do is just send a PM to anyone who I thought could do the job well. From there, maybe you could initially offer them moderator status for 3 months sort of as a trial period. If they perform well, great, keep them on board. If their performance is sub-standard, well then you can simply demote them at the end of the 3 months and no one's feelings will be hurt.

One more thing is that I think it's extremely important for th moderator to be active, so if you decide to ask a friend to help you, pick someone who you know has an interest in your forum.

Good luck!

I also try to find people that use correct spelling and grammar, and post frequently. If the poster does not put the effort into their own posts, I find it hard to believe they would be good at scanning through other people's posts.

i have about 500 members now and i have appointed 7 moderators... out of all the moderators, only 1 is REALLY active... the others would occasionally post probably 1-5 posts a week...

i will be looking for moderators soon, and dispatch the other moderators...

Yeh I think you need to find a couple more moderators that are able to post more regularly.  That would be a help for your forum.