Form 11 is usually for those with material non-PAYE income. Basically the same forms used by any self-employed people.
Form 12 is for those with substantially most of their income from PAYE and with perhaps small other income, dividends or small amount of rent. Given that your rental property has been tax loss making so far, you could probably use F12. Also, as it is a loss, no tax charge would have arisen. ( assuming all other income & claims for the relevant years are in order.)
What I think you could do is construct Income / Expenditure for all years. Get cumulative loss forward to date. File 2008 with actual 2008 figures and note the cumulative loss forward. Mention in cover note that you realise that you should have filed but given the loss will they require returns or can you start the accumulated loss at 2008 and go from there forward. Revenue are often loathe to create paperwork for no result and if it is clear that the property was tax lossmaking up to 2008 they may accept this approach. However, if they require reutrns to be filed you will have to file them.
Bear in mind, that if your other affairs are in order there is no problem but if you have under/overpaid in years 2003 on, you would be liable for any underpayment but you would only be given credit for any overpayments from 2005 on ( under the 4 year rule )