Hi C Refrow,
Below is a list I have of resources, both audio and online reading-- I just copied and pasted as I am on an iPod.
I would suggest the Baltimore Catechism if you are looking for basic theology, and Radio Replies, which is apologetic in nature, for a more advanced presentation. You may get better suggestions if you are more specific about what you are looking for.
I am not sure what you mean by reading about catechetics?
Here goes:
My list may be superceded by this one
catholicview.wordpress.com/resources-for-catholics-and-other-inquiring-minds/free-catholic-audio/
Forgot this one!!! Where I found John Rao’s talks
alabamacatholicresources.com/
Links:
Quick articles I found helpful (or regretted not having sooner!)
Handling people’s “drive-by” comments about the Church
About Discernment and decision-m
aking
mrstreasures.wordpress.com/2013/07/08/are-you-really-doing-the-will-of-god/
When has one prayed enough? Good advice and good comments too!
Mp3 audio Scriptural Rosary
A review of iPieta. Run a search for the version on your platform or search for it in your platform’s store if you want to get it.
Teacher’s edition of Baltimore Catechism which includes explanations
A page on which are linked the sections of several catechisms, including the current CCC, under the appropriate topic, so if you are studying one topic in one, you can easily find alternate explanations.
A note on the Baltimore Cathecism: this comes in several versions some of which are simplified for the use of children. I hope to find one page listing them all soon.
Radio Replies These were a series of collections of letters and answers to 2 Australian priests from the 1930s to the 1960s or so. These are excellent, and a bonus for me is I always feet like my mind has been sharpened up when I read them

Very thorough explanations of Catholic teaching, and often answering somewhat antagonistic questions and so an excellent resource for people who get a lot of questions about their Faith.
Sonitus Sanctus. A blog containing links to many online audio resources of interest to Catholics. Altho he has not posted very much since he married and had a baby, there was so much up there that it is also a wonderful resource.
Sermons in MP3 and podcast version on many Catholic topics. On the right, there are headings to where the sermons are sorted by topic, so this is helpful when learning.
Catholic ebooks, similar to Sontitus Santus above, only with Catholic e-books online.
Don’t be overwhelmed by all this; it is a list I have developed over the course of many years and should be considered as more of a library than a list of textbooks for one course.