Easy, I thought, I will go to the advanced set up page for the router & enable the encryption. But I managed to secure myself out of my own network

I thought maybe the first time it asked me for a password it would use that, no. I thought on enabling the security feature it would ask me to create a password, no. It would appear to not be as idiot proof as I hoped. I tried all kind of "usual" initial passwords to no avail & really didn't know what to do, luckily the router had a reset hole.
Anyone know of a good step by step guide? I have tried google but I just keep getting shops selling my type of router. (Also I was a bit confused by the initial choice of WEP/WAP security feature).
any advice from you clever guys?