I teach secondary English; I think the lesson plan above about the "Bluebottle" poem sounds great.
These things might seem obvious, but if they don´t, I hope you find them helpful.
I recommend you try to get the students to discuss in small groups (pairs is probably easiest in a 30 minute lesson, but they might be sat at grouped tables of 4 or 6) before going into whole class discussion. If they´re sat in 4s or 6s, you could even do pair, then group, then whole class.
Try to ensure that everyone in the class speaks in whole class discussion at some point - this could include reading aloud - some will volunteer but others will need to be "picked on" or encouraged to speak.
Also when the students give their ideas in whole class discussion, try to avoid repeating or paraphrasing what they say - the danger of doing that is that the students will stop listening to each other and will just wait for your summary.
Practise running through your lesson MANY times in advance! Work out how long it takes things to do like give out any sheets or resources (and collect them back in, if that´s part of your lesson plan).
Don´t be afraid to deviate from your lesson plan. The person or people observing will be happier to see you react to the students in front of you and the situation than to follow your lesson plan doggedly. The same goes for if you run out of time or end up with spare time - improvise as you see fit. On the same note, make sure you are wearing a watch and / or have a clock that is clearly visible to you (and that the watch or clock is accurate!)
Have a back-up plan for if technology fails you.
I hope it goes well!