This is a lesson aimed more at pre-intermediate / intermediate level learners that “introduces” SHOULD and SHOULDN’T. Though it can be used to revise the language point if learners have met it previously!
It is based around using Should / Shouldn’t for expressing advice within the “good idea” “bad idea” range – obviously this is not the only use of Should!
The lesson plan, which is relatively straightforward is available to download here: teflgeek – Should and Shouldn’t.
It’s ready to go as is – doesn’t need any additional planning or preparation.
The good idea / bad idea graphic above comes from a kids TV show – Animaniacs – which I remember from my earlier years ( I don’t know if it’s still going). Here is a Google video search selection for the segements, which could be used to extend or introduce the general topic with younger learners (or adults?).
Some additional online “should / shouldn’t” practice activities:
A flash gapfill task from englishgrammarsecrets.com
A sentence matching task from OUP’s Natural English Pre-Intermediate coursebook site
A type-the-answer gapfill task from esl-lounge.com
And finally – a downloadable Garfield based worksheet by Zailda Coirano posted on docstoc.com
teflgeek 
Tuesday 5 April 2011 at 19:40
Hi David Petrie,
I’ve seen you are posting in TeacherLingo, so I clicked on your post there to peek your site.
I like to learn from other teachers. I just read your lesson plan on Should and Shouldn’t. Thank you because I had the chance to see how other teachers plan the classes and try to implement further ways and stuff in my classes.
As well, to be honest, I view other blogs to improve my English.
The class plan is outfitted nice.
Fernando Diez Gallego
Teacher of English – Teacher trainer
Granada (Spain)
http://fernandoexperiences.blogspot.com
Wednesday 6 April 2011 at 10:43
Hi Fernanado,
I’m glad you like it! I have some other lesson plans floating around the blog somewhere that might interest you. If there’s something you’d like to see on the blog, just let me know and I’ll see what I can do!
All the best,
David
Wednesday 6 April 2011 at 11:43
Hi David,
I appreciate your disposal for me to see other class plans. I’ll bear this in mind, so as to check your site sometimes from now on. Like I said, I learn from the way other colleagues teach, so different from mine.
Fernando
http://fernandoexperiences.blogspot.com