recovering rent deposit

[sib123]

I sublet an apartment from a friend two years ago. I gave her first month,last month and one month security. The landlord was aware that I was subletting the apartment as this was something my friend had been doing for a while.The reason I had to give her last months rent was because she spent a previous tennant's deposit and when I came in she used my last months rent to cover the previous tennant's last month rent.The landlord did not require 3month's rent upfront only 2 months so this was something she was doing on her own. After living in the apartment for a year the landlord called me and said my friend had been paying the rent very late and even bounced a few checks.He said that he was fed up with her and was no longer going to let her sublet the apartment and instead he made me the legal tennant(there was no lease so he was able to do that) So my friend and I discussed the fact that she owed me last month's rent($1200)and that she had every intention of paying me back. I agreed to let her make monthy payments back in december.Since then she has made no attempt to pay me back,i sent her a certified letter stating that if she did not return the money i would take it to small claims court,but she never signed for the letter and it was sent back to me.I now want to take this to small claims.I have the sublet agreement that we both signed stating how much money i gave her up front.i have all the bank receipts for the rent that i deposited into her account,and the landlord has agreed to write a letter stating exactly when and why she was no longer the legal tennant. Is here anything else i should have to bring to court? Also how do I make sure she receives the letter from the court with the date to appear.I know the court will send a certified letter but what if she does'nt bother to pick it up at the post office and it gets returned?If she sees it is from the court in our town she will know exactly what it is(she has been taken to small claims before by a previous tennant and lost)I want to make sure I have all the proper evidence going into court.