I'm a Kiwi school teacher whose been here for coming on 7 years, on consecutive workpermits for the same school/education authority. Around March, I started compiling my stuff for the ILR application, and did my Life in the UK test then too.
'Telemachus' - the dude who posted similarly just before me, did a brilliant job of describing the 'process' at the PEO in Croydon, so I won't go into too much detail. I had a 1pm appointment, but by the time I sat down in that cavernous processing area, it was 1.30, and I wasn't actually seen until about 4pm. If I had to do it again, I would've booked it earlier - turns out they had a computer glitch or something!
After security, I had my document screening, standing up at a counter: it was slightly nerve-wracking. The guy ran through my application and documents meticulously. He questioned me about the fact that I'd declared my 'unspent' fixed-penalty speeding fine. I looked him in the eye and told him that I thought it was better to be up-front, even if it wasn't officially grounds for declining my application. He affirmed this by saying I was right to declare anything like that. Then he sent me up stairs to pay my money.
Brief panic attack as I foregt the PIN for my seldom-used credit card, then success! And on to the wait....When I was finally seen, my case-dude 'Steve' rattled through what he considered to be the essential documents, not saying a word about my speeding fine, and not even asking for my bank statements. This worried me initially, so I asked if there was any problem. He looked up briefly with half a smile and told me that my payslips 'told-the-tale' but he thanked me for bringing the bank statements with me anyway. Anticlimactic.
Thanks again, to those who helped me out on my few posts here.
Below is my document list - note the endorsed/notorised docs (I was dumb enough to schedule my PEO appointment for the 31st May - forgetting that my last bank-statement and payslip wouldn't be ready until a week later). UKBA accepted the internet-banking printouts as long as they were endorsed by the issuing bank - I took them in and my bank stamped them - no problemo. I made a duplicate copy of everything - in a pretty, polly-pocketed dossier ... UKBA didn't want it, despite what it says on the application form
The letter from my boss, was literally one adapted from a sticky on this forum - the one with the little table built in to catalogue absences 
SET-O May 2011 version
LitUK pass letter
3xpayslips
1xnotorised latest printout from my payroll manager
3xbank statements
1xbank-authorised print out of previous weeks transactions (showing my salary going in)
1xletter from my head-teacher confirming that all of my absences were on school holidays, and my continuing employment
1xletter from my Local Education Authority HR dept confirming my salary and continuous workpermit/employment history
1xpaper copy of my drivers licence showing the recent speeding ticket
Happy to help, if anyone wants more detail.