Here is a site which discusses learning theories:
I think you already have enough information about learning theories. What you need to do now is to think of how these theories are useful for us to learn a language. (as you rightly say "theories is useful in your own learning of English"}
If you go to google.com and search for "learning theories" + "language teaching" you will get a lot of sites with useful information.
For example have a look at this page: http://www.google.com/search
There is a PowerPoint Presentation on this page which discusses different learning theories.
If you download the PPT file and watch the Presentation you will get the gist of each learning theory.
For example you will get to know that
1. doing a language drill in the class is based on behaviouristic learning theory
2. giving a problem solving task for students is based on cognitive learning theory
3. asking the students to talk about their own likes and dislikes is based on affective learning theory.
Find some classroom activities to supplement the theoretical aspects you have discussed in your paper.
Please go to this site: http://teachingstylesonline
You will find some simple activities for teaching the Present Perfect Tense in class.
For each activity you can try to find out the learning theory it is based on.
You can also take a multilingual activity like the one given in this site: http://teachingstylesonline
You can try to identify the learning theory that is the basis for each activity.
All the best for your assignment Megha.
Keep in touch and let me know how it develops.