Well, I'm doing it for AS and also have my exam next week, so I'm not sure how much detail is needed for GCSE, but here's a brief summary:
Fact vs fancy: Gradgrind, Bounderby and Bitzer are obsessed with 'hard facts' and measuring everything statistically. Even with regards to his daughter's marriage, Gradrgind can't bear to resort to emotion or any other human qualities. Fancy is represnted by the circus and the pantomime theme of the play, with Mrs. Sparsit being referred to as a witch, Mr. Bounderby as a giant and so on. Louis and Tom peeping at the circus, and their eventual breakdowns, show that fancy is necessary, and Sissy teaches Gradgrind the power of the heart.
Education: Dickens criticised the education system, which tried to cram the 'little vessels' full of facts. Teachers like M'Choakumchild know a lot of facts, but only seek to drive fancy from the hearts of the children. This is illustrated in a fanciful way by comparing him to Morgiana of 'Ali Baba and the 40 thieves', who poured boiling oil on thieves hiding in jars.
Utilitarianism: The education system helps to instill this in students. The reason Sissy fails is because she cares too much about individuals; ie she doesn't agree that if 'only 1 out of 100 people die, it's good' because she knows that even one death causes a lot of pain and suffering. The trade union is also evidence of this when Stephen is ostracised for the good of the majority.
Religion: Dickens was very critical of the Sabbatarian movement which tried to restrict Sunday activities. It is sarcastically said that the larks were singing 'although it was Sunday.' The chapels are compared to warehouses and no working-class characters attend them, although Stephen and probably Rachael are very religious.
Self-interest: Bitzer shows this at the end when he wants to prevent Tom's escape in order to turn him in and be promoted at the bank. He says he must have a heart because of circulation, and quotes Gradgrind's theory that 'the whole social system is a question of self-interest.'
Industrialisation: Dickens was critical of the effects of this, which can be seen in the descriptions of Coketown as crowded and polluted. He also criticsed the laissez-faire economic policies, which manufacturers such as Bounderby used to get out of installing safety devices in factories, covering up pit-shatfs and controlling smoke/gases etc.
Social class: The novel is all about the exploitation of the working-class by the rich, and how Victorian society ensured that the rich would get richer while the poor got poorer.
Politics: Harthouse represents cynical politicians who easily got bored with what they were doing, and Gradgrind's 'blue books' were full of facts and statistics.
I remembered all that off the top of my head!
I'm so proud lol.