This may be a stupid question but Im very new to this. Am I able to download retro Rom's to my R4DS? e.g Wonder Boy. Your help is appreciated!
Go to http://www.linfoxdomain.com/nintendo/ds/ Click on the Emulators for DS section. That's a pretty good list of what's available to play on your DS.
Check out http://nintendo-ds.dcemu.co.uk/ just make sure to patch the emulators to work with your card
There's a nice list of Emulators for DS in the NDS Trading Station. Check it out. Older emulators might need DLDI patching, which would be unlikely.