Okay,this is what I recommend you do:
1)Register on the RuneLocus, Rune-Server, Moparscape and Silabsoft.
2)Work out what kind of server you are gonna want to create. The main types are 317, 474, 503 and 508. These range from old school runescape (317) to when the new graphics came out (508).
3)Once you have done that, browse the appropriate download section on each site and find a source/base that you like. This is what you will edit to make your server just how you want it.
4)Now find a decent IP changer client for your server. If you are using a 317 source then use the Moparscape webclient but if you are using 503-508 then use something like Umair's IP changer.
5)Now you need to go into the source you downloaded and find a file called run or something along those lines. Double click it and then open your client in the same way. If it asks for an IP address then put in localhost.
6)Finally, browse the forums I mentioned for guides and tutorials and start using them to impove your server.