As a minimum what maternity pay/ benefits would I qualify for?

[Chasingcars]

Planning a family next year, but a bit confused over what pay/benefits I would be entitled to. I understand the basic maternity pay and SMP but my friend said she got a one off grant of £250 i think it was once she got to 20 something weeks? Also she gets child allowance of about £20 a week.
Are both of these things regardless of salary?
My partner and I both have good jobs and good salaries so we are not looking to, or expecting to claim any benefits but just intertest what comes 'as standard' when you have a baby so we canwork out if we can actually afford children!!
Also, I know there was talk of but not sure if it did happen (gov website doesnt appear to be that up to date) if i take a full year from work does SMP still only cover upto 39 weeks or is now confirmed to pay for the full 52 weeks?
Any info would be appreciated, thanks!

[themas]

1. There is a "health in Pregnancy" grant of £190 - not means tested.
2. Child benefit - £20 p wk for the first child - is not means tested.
3. SMP is paid for 39 weeks - the first 6 wks at (I think) 90% of gross pay, & the rest at a flat rate of a bit over £100 p wk. This assumes you do not have a better entitlement from your employment contract.
4. If you give up work the family income will decrease & you may find you are entitled to Child Tax Credit. This is means tested but can be paid (at a low rate) up to gross family income of £50,000 pa +. If you return to work & need paid for child care (with registered or approved child minders) a substantial % of the cost can be included in the Tax Credit.
5. If you do have an entitlement to Tax Credits it is possible you may also be eligible for a one off "Surestart" maternity grant of £500.