Pierremontquaker

Hi, at the moment I have a separate kitchen, and then a separate dining room leading on to the conservatory. I am looking at knocking the wall between the kitchen and dining room and creating a kitchen/diner with an island, new roof on the conservatory with bi-folding doors - in other words all singing and all dancing, the full works space. See pics below. The trouble is I don't know where to start in terms of the planning etc. I know someone who could potentially could do it - I will get him round, but I am wanting ideas, and want everything to be planned to the fine detail. Are there any websites/forums I can join, contact etc? I am based in the North East (Darlo). Thanks for looking, and any ideas comments would be appreciated. (apologies for the mess, we are having a sort out)