To learn this difficult tense you first have to learn the past participles. Regular verbs just add the ending -ed but you have to memorise the irregular one. Here is a mind map which might help you memorise the irregular verbs first
Once you think you know the irregular verbs, it is time to practise them. Try these two wonderful games called Teacher Invaders and Half a minute.
Now that you really know the past participles you can start learning the present perfect tense. Listen to the song Brighton in the rain and complete its lyrics.
If you complete the lyrics correctly you can play the game called Angry Finches. Good luck and enjoy.
So now you know the form of present perfect tenhttp://www.aj3000.orgse. Now, it is time to use it correctly. So you should try Present Perfect vs Past Simple.
You can find free graded readers for learners of English at www.aj3000.com