Please bear with me as I am very new to Fly Fishing.

I am spending a week at Stonegarthside Hall, Kershopefoot in April and whilst there would like to do some fly fishing on the river Liddel.
Can anyone give me advice as to where I can get a permit from, good locations to fish (I will have my waders with me) and any other info that might help me.
I have done a little research on the web but can't find anything very comprehensive.
If you can advise me in anyway I would very much appreciate it.
Thanks