Here are some great resources to get you started.

Mount Zion Bible Institute

Simply start at the top and work your way down. You'll finish richer for the experience and education. If you have friends growing in this then work through them together. Take turns facilitating. Answer keys are there too. If you don't have someone to work with, do it yourself. I've done several of these myself.

You can also go to Capitol Hill Baptist Church » Core Seminars and download resources. These, in addition to much of what's been shared already, would be very useful.

Both of these sites have apologetics classes. The order of Capitol Hill's resources is alphabetical, so I'd simply list them from basic to more advanced as best as your able, and work through them, if you like their material. You might mix and match too. We use materials from both for our church and have been enriched through the study.

As for when to start more in-depth study of apologetics: That's a tough call. Perhaps when you are not enamored with apologetics. Maybe when you desire to do it because your heart breaks for those lead astray. Your heart must be focused on Christ. Remember, knowing God's Word is the best apologetic on the planet. It will prepare you and protect you from any error or false teaching. It will make you an awesome weapon in the hands of God for the building up of His church. But merely being an apologetic, even an awesome debater, could simply make you a distraction...

May God bless your efforts and captivate your heart.

__________________
For the Glory of our King,
Joe Johnson
Slave of Christ, husband, father, Preacherboy at Cornerstone Community Church, Escanaba, MI. and TMS graduate. Personal website - SoundLife.org

I do not know, and I do not say, that a person cannot believe in Revelation and in evolution, too, for a man may believe that which is infinitely wise and also that which is only asinine. ~ CHS