HELP.....regards to ILR Application and date

hi there......heres my story..

I received my Spousal Visa was issued to me on the 28 May 2009
I arrived in the UK on the 9 July 2009
My visa expires on the 28 Aug 2011

as you can see...there was a short time of 1 month and a half before arriving in the UK......I was wanting to know at the earliest, what date i would have to apply for my ILR?

Thankyou in advance for our help....

Also.....need another problem answered if possible.......what would be the best way to apply for my ILR ......by post or in person?........i am a little confused as to which way to go on this ....i have rang HO and they said that post is my only option under my spousal visa catagory...i cannot understand this as i have noticed throughout this forum in other posts that alot of people who have applied for ILR setM....done so by PEO????...........................could you or anyone else in the knowledge please simplify this for me as i dont want to get the initial first step wrong......