The cache is a small container hidden at the beginning of a public footpath on Darlington Road. Although the road can get quite busy, you should be able to stay mostly hidden from sight when searching.
In order to jump start the trading, I've initially added 10 foreign coins that i've come across:
5 Baht from Thailand (2008)
50 Kurus from Turkey (2009)
25 Kurus from Turkey (2009)
25 Cents from the British East Caribbean States (1955)
1 Dirham from the United Arab Emirates (2007)
10 Cents from Malta (1986)
1 Peseta from Spain (1963)
1 Penny from Ireland (1979)
10 Lipa from Croatia (2009)
25 Cents from Trinidad and Tobago (1984)
And now for the cache trading rules:
1) If you don't want to trade, you don't have to. Feel free to just sign the log.
2) If you take a coin, you MUST leave one. The only way this cache will work is if everyone does one-for-one trades, unless you leave extra of course, in which case, Great!!! You're helping to keep the coin cache alive 
3) No modern English coins. The idea is to have coins in the cache that are interesting and not seen on a day-to-day basis. However coins from dependencies like Jersey, Guernsey, Isle of Man, Gibraltar are all welcome.
4) For the above reason, try to avoid common US coins and Euros, but if that's all you have then feel free to swap them
Good Luck and have a nice time trading 