Hi Yecats2885,
First of all, congratulations on your pregnancy. xxx
As long as you are entitled your employer should pay you 6 weeks of 90% average weekly earnings followed by 33 weeks of £123.06 (for 2009/10 tax year) or the 90% average whichever is lower.
So for example only: If your 90% weekly average earnings calculate to be £103 per week you would receive all 39 weeks at £103 per week. If your 90% weekly average earnings calculate to be £140 per week you would receive the first 6 weeks at the £140, then 33 weeks of £123.06 (for 2009/10 tax year).
The 8 week average is not calculated on the 8 weeks immediately prior to you commencing maternity leave. The 8 week period used are the 8 weeks prior to the 15th week before your baby is due.
If you are absent from work due to a pregnancy related illness at the 4th week before the baby is due your maternity leave would need to commence automatically.
With regards to your partner I do not know anything about that - sorry.
Hope this helps and good luck xxx