Those were the original instructions, use the following now:
1) Update - The update broke my functioning Google Market and my root
2) Once the Kobo app setup has finished running (if it is required, I don't remember at this point) go to menu -> settings -> applications. Ensure "Unknown Sources" is checked, then press development and enable "USB debugging".
3) Download and install GingerBreak-V1.20.apk (can be googled), once Gingerbreak is installed click on the "root device". Kobo will restart 2 or 3 times (I can't remember) and you will see a SuperUser (with a green pirate-sort of looking icon) in the programs menu once it has sucessfully installed.
4) I did a factory reset on my device at this point (this may or may not be required, but since I had google market on there last time the system and the data was messed up so that was the solution)To perform factory default (Hold VOL UP and PWR) then finished the Kobo setup wizard.
5) I downloaded and extracted gapps-gb-20110828-signed.zip from the cyanogenmod website and put it on my Kobo's external SD card.
6) Download and install File Expert -
http://www.xageek.com/en/
7) Open File Expert, menu button -> more -> settings -> File Explorer Settings -> Tick Root Explorer. SuperUser window will appear, say allow.
8) Copied the following files to /system/app using File Expert (had to mount /system as Read Write first: use File Expert -> menu button -> Mount -> Mount as Read Write):
GenieWidget.apk
GoogleBackupTransport.apk
GoogleCalendarSyncAdapter.apk
GoogleContactsSyncAdapter.apk
GoogleFeedback.apk
GooglePartnerSetup.apk
GoogleServicesFramework.apk
MarketUpdater.apk
MediaUploader.apk
NetworkLocation.apk
OneTimeInitializer.apk
Vending.apk
9) Set the permissions to 644 (Owner : read + write, group read, everyone read) on each one of the files listed in step 8. This step is VERY important!
10) Changed the ownership to 0/0 (root/root) on each of those files listed in step 8. (I think this step might be optional)
11) Shut down kobo and restart it (in order for the new system files to appear the system needs to be restarted).
12) Went into accounts and added my google account just as I would on any normal android device.
13) Launched market and installed gmail and youtube!