I think the most effective study is study that involves things you actually care about or areas of your life that you actually want to see changed.
In my personal journal I have undertaken a course of study that helps develop me spiritually in the following areas:
-As a Child of God
-As a Husband
-As a Father
-As a co-worker (I spend 8 hours a day at work -- chances are I can let my light shine there)
-As a Friend
I plan to study the scriptures in that light.
One thing that I do in my journal writing (and I highly recommend this during your scripture study) is to write each entry as a dialogue between Jesus Christ and myself. I come to Him with concerns or questions or I simply ask Him to help me and guide me in my personal study. Then I listen to what I feel as best I can and I record what I feel from Him by way of reply. Sometimes it is challenging to put what I feel into words. Communication Spirit to spirit is very pure. Sometimes words don't do justice.
As far as topics, the following could probably last you a lifetime:
Faith (as well as Hope and Charity)
Repentance
Baptism
Gift of Holy Ghost
But it is crucial that you study because you WANT TO not because you HAVE TO. Forcing yourself to study won't do much good. Study what interests you, and as you include the Lord, He will guide you into the areas that are needful.
Good luck!
Tom
PS: Elder Bednar has given some GREAT talks on scripture study:
A Reservoir of Living Water - David A. Bednar
also
Understanding the Importance of Scripture Study