pigcon1 what you say is interesting.
I passed the 11+ for the grammar school. I never had any help from parents at all, either in primary or secondary, from my parents. No parent hand in any of my primary school art projects/competitions/spelling/maths tests. I remember once aged 8 I'd forgotten to do the weekend maths homework for the Monday and my mum was really resentful having to sit with me to do it on the Sunday night after I got out of bed at night in a panic when I remembered - I didn't ask her again. Grammar school was an alien world to my parents, and I think they thought it was like "private school" where you would be spoon-fed everything in a very nurturing, interested environment. In reality it was a brisk paced hard-nosed academic environment with no pastoral care or student support at all, where you swam or sank. I really struggled at times by myself and at some point I realised that other students' parents did help/tutor them through homework or at least took an interest in their subjects, timetabling, run them to after school sports activities etc and would help finding additional resources.
As a parent, I take a really active interest in my DCs work, homework etc and I know my Y8s timetable off by heart (not because I've studied it, but because I take an interest generally in what they have on the next day). I know when they have tests and assessments in school, what it entails and what work they have done for it. I have shown them how to revise and prioritise, and if they get stuck occasionally they know I am on hand to help either from my own knowledge (limited in some subjects, better in others!) but mainly in getting additional resources for them, such as books.
I did well enough(ish) at the grammar, but I know I could have achieved more with a more nurturing home environment. I know my parents were limited by their own poor education (not their fault) but they could at least have helped with the nuturing side. Instead I felt uncomfortably like they were slightly contemptuous of the "posh grammar school" and if I suggested I was lacking in understanding on a topic, their response would be along the lines of "What are you bloody learning at that bloody school then? Is everyone else struggling or is it just you? Because I'll go down there and I'll tell that bloody teacher she's not doing her bloody job properly!" etc. If I said some students did get it and the whole class wasn't in the dark, then therefore it must be my fault for not bloody listening properly. So I was stuck either way. 
I don't want my DCs to feel they can't ask me for help and support like that.