A few notes to outline the "technical" requirements to ensure that the Route Index works effectively - covering file formats and the text used for searching.
GPX files
The .gpx format has been adopted by most mapping systems to enable exchange of data between different, proprietary software and online services. In most cases the tool used to create your route will have an option to Save As or Export the route data as a .gpx file - follow the instructions and save the file on your computer ready to upload to the Route Index. That's it!
If your route has more than one .gpx file (perhaps a file per day) you will need to create a .zip file holding all the .gpx files. Most operating systems have this feature in-built, or there are a number of freeware options available.
Note : Garmin, perhaps the most popular GPS brand, has its own file format .tcx - if you have your route in that format you will need to convert it to .gpx (The free GPS-Babel software is one conversion tool). If you want to submit both a .gpx and the original .tcx file then you will need to create a .zip file to upload.
Routes as text listings/instructions
If your route is written as a list of places or other instructions it can be added to the Route Index as a .pdf file for users to download and read/print. Most word processing software has the option to save documents in the .pdf format (If not PrimoPDF is a useful freeware tool). The ideal for .pdf uploads is a single file of the complete route, however if it's in more than one file you will need to create a .zip file.
Text for searching
A brief description of the route using keywords that are likely to be searched on by the site visitors ... the text needs to have a title, the file type and be brief, perhaps including a list of overnight stops and possibly key places of interest (avoid the obvious "Land's End" or "John O'Groats" or other route start places)
AND do make sure that spelling is correct - the search facility will ONLY match precise words! It will also help the appearance of the Route Index if the text is typed conventionally using UPPER and lower-case (and no txt spk!)
It might be useful to draft the proposed text for your entry before you go to the file upload - you can then copy and paste the final text. Editing text after the entry has been made can only be done from the system end .... I don't want to have to do too much of that :-)
Maps and mapping
The .gpx files that site visitors download should be possible to apply to most software mapping systems and online services - a small word of warning : in my experience, Google Maps is an excellent free tool used to drive almost all online services BUT there are many inaccuracies in the mapping data - roads that are shown that don't exist and roads that are on the ground but not on the Google maps.