There are various locations at which you can print A0 poster, such as the Library and Kings Buildings.  Probably the easiest way to print a poster is via Graphics Lab.

 * create a pdf of your poster in whichever way you wish.  Graphics Lab will make sure it is scaled correctly and printed in the correct orientation.
 
 * get in touch with admin (level2admin@inf.ed.ac.uk) and ask them to set up an eIT to pay for the poster.  You will need to let them know the cost - at the time of writing, the cost was £10 for plain and £22 for glossy posters - and the grant that should pay for it.  You can also pay Graphics Lab in cash, but then you will need to pay VAT.

 * email your pdf to graphicslab@ed.ac.uk.  Let them know the eIT has been set up (they should already know this).  If you want a non-glossy poster, ask for draft quality - otherwise they will print a glossy poster.

 * wait for them to email you to tell you it is ready, and then pop down to the Hugh Robson building to collect it.

 * allow a minimum of 24 hours - 2 or 3 days would be better, in case they are very busy.