Here is one more link with a nice Gurumukhi alphabet song also. I hope you will enjoy and learn from these sites. I learnt it on line and I practiced by reading Gurumukhi Hukamnama from Harmandir Sahib every day. Regards and best wishes.
This is one link that I will pursue.
Mangat Rai Bharwaj: Colloquial Panjabi is supplemented by 2 cassettes @ 60 mins. If you make full use of the set, you'll have a good basic knowledge.
The transcription system in C. Shackle: Punjabi (Teach yourself books) might be more scholarly, but even to a language nut like me, it is not too transparent. My copy is 1972, though, so things may have changed.
Unfortunately (I think), neither book uses Gurmukhi throughout, almost only in the vocabulary sections.
Despite those books (and others) and the link mentioned (which has a couple of sound examples to illustrate), I still don't understand the tones. And Swedish has two tones, and I'm studying Chinese... In addition, are the same tones used in all varieties of Panjabi, and does this feature replace the non-aspirated/aspirated distinction (like b/bh)?