Hi Olive
Do not cut out bits of paper and try and attach them to the form - it will make it impossible for them to scan your form properly.
Keep all the extra sheets together. On each sheet it should be clear which question you are answering. You don't have to type up the whole question, but I would put the question number and the topic. On the form I would put in the white box "see attached sheet number X" (putting the appropriate number).
They ask you not to staple the pages. The preferred option is to put a hole punch in one corner and put a tie through them. Make sure you make it clear on the end of the form there are additional pages - I know it should seem obvious, but it's a final reminder to them that it is not just the form, because it is possible for them to become separated. Glad you have your name and NI number on all the pages.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems