Hi Jayne,
I ran Edinburgh last year, and will be running again this year, it`s a great course if you are competing in your first marathon distance race, relatively flat, and not too crowded at the start in princess street.

Two things worth considering, wind and posibility of showers of rain!
The course runs down along the estuary, and last year we had a head wind and drizzle to run against on the outward 16 mile leg of the course, although the wind was a benefit after the turn point when it was behind you.

I would reccomend that you take a long sleve top, that you could wear under your running vest, and I would also reccomend a shower/wind proof light weight jacket.

Something like a Montane Featherlite Marathon Jacket, it folds into its own mesh bag and is then about the size if your fist! and weighs 136g or 4.6oz, so you won`t even notice it. Just strap it to your bum bag.

www.ultralightoutdoorgear.co.uk/shop/shop.php?c=viewproduct&pid=376&cat=18&maincat=7&start=0&sid=sid6bee72986c1299ac5dde174ed3d6f923

or even this one www.runnersneed.co.uk/shopping/item.aspx?id=4900

featured inTOP Shops on the left hand menu of "The Running Bug", which is cheaper and has detachable sleves

That way, if the weather is favouable run with just your vest, with the option of slipping the jacket on when needed.

I ran in long bottoms aswell last year, and as long as they are running tights, you should be fine.
You will need warm clothes for immediately after the run, which finishes at Mussleburgh Race course. as you will hang about waiting for the busses to get you back into town.
regards, gromit

thanks gromit, i hope it doesnt rain to hard, looking forward to it though, didnt know about the bus though? i take it if i have a lift i dont need to get on bus,as my family will be there.