Are you going to be doing something new in September? Perhaps you’ll be taking a different year group or teaching a subject that you haven’t taken before. These are going to be scary and exciting times, but with the right preparation it can be fun for you and good for your pupils.

Sophie Parker from Sudbourne primary school in Lambeth, south London, taught a mixed Years 1 and 2 class for the first time this year. Not a big deal, you might think, for someone who’d taught Years 3 and 4 successfully for three years, but she was aghast at how different it was.

“It was like starting all over again,” she says. “My whole teacher persona had to change. I had to get used to a different curriculum and a completely different style of teaching.”

The increase in daily parental contact that stems teaching younger children enriched the experience but added to the pressure. Ms Parker went from being very confident and knowing the curriculum so well that she could almost teach on autopilot to having absolutely no confidence at all.

For the first half-term she relied heavily on her colleagues, something she wasn’t used to doing. In fact, it was a good idea and, in spite of the hard work, Sophie recommends other people change age group. “I have learnt so much, it’s massively rewarding. I understand children so much more and younger children are so responsive, so clever, so interested in absolutely everything - it’s really very magical. I’m a better teacher all round now,” she says.

If you teach a different year group, you need to think how children at that age learn, and what is the best way to teach them. Teaching reception is not the same as Year 1.

Observing an effective colleague in your school or elsewhere is a good way to start. Of course, the same basic principles apply in education whether you’re teaching science to 16-year-olds or Spanish to six-year-olds. You need to know what the children can do, and then bridge the next steps.

Then there’s subject knowledge. To teach anything well, you need to know what you’re talking about, to be prepared for those weird questions that some children ask, as well as all those misunderstandings you didn’t think were possible. They’ll test how deep your knowledge is: if you’re only ever one page ahead of the children, you’ll find yourself in deep water.

The forum for new teachers on the TES website is full of tales of newly qualified staff being asked to turn their hand to subjects they’re not qualified in. Someone who’s just finishing her PGCE in English said at her interview for a job starting in September that she would be happy to teach media studies. “It now transpires that I’m the only person teaching it and the head wants to know which syllabus I want to use,” she writes.

“She also wants me to prepare all schemes of work and give her a full breakdown of the budget I will require. There are no resources, no experienced staff in this subject, and the only help on the horizon is a one-day training course on how to teach media studies.”

So, three months before she’s employed and two months before she qualifies as a teacher, she’s having outrageous demands made on her. Luckily, she’s protected for her first year by the induction regulations from what the Department for Education and Skills describes as “unreasonable demands”, but she needs to raise her concerns with the headteacher and local education authority as soon as possible.

Dr Kevan Bleach, assistant head at Sneyd community school in Walsall, is adamant that no one should be coerced into teaching a subject for which they’re ill-equipped. It’s not fair on students or teachers and it can cause a lot of stress.

He believes that teachers who are teaching outside their own specialism should not only have early access to a suitable training course but that they should have what he calls “personal professional development time” for studying and to develop resources.

Dr Bleach ensures that in his school they are supported with a detailed scheme of work, a curriculum map, and teaching resource pack. “I would also expect either the head of department or another experienced colleague to act as a mentor and meet regularly,” he says.

Almost everything that we have to teach has been taught thousands of times before so there is no need to reinvent the wheel. But people aren’t psychic, so speak up if there are things you don’t understand. Most people are willing to help even if they are busy, but ask for something concrete.

Do you need help with resources? Is there some part of the subject you just don’t understand?

Helen Lazenby of St Charles RC primary in Kensington, west London, is moving year groups because after nine years in infants she wants key stage 2 experience. Although she admits to feeling nervous, she says: “It’s quite exciting and a chance to get my teeth into something new.”

She’s already started talking to teachers of the year group and observed some lessons and is planning to read curriculum books over the summer.

So if you’re making a change in September, do your best for the kids. And you’ll probably find it’s best for you too.

Sara Bubb’s latest book, The Insider’s Guide to Early Professional Development - succeed in your first five years, is published by TESRoutledgeFalmer, pound;12.99.