UTF-8 question

Hello,
I have implemented a java application which extracts information from an iso-8859-1 encoded XML file using the JDOM parser and feeds it into a postgresql database. Everything is running on linux. I am using Postgres 7.1.3 and jdbc7.0-1.1. Now I would like to do the same thing with UTF-8 encoded XML files.
Since I have no experience with unicode and utf-8 I would like to know whether I have to expect difficulties at the JDBC and Postgres side of the thing (my Postgres database is already configured for unicode).
I would also like to know a simple way to feed some unicode characters into a Postgres database, get them out again, and display them on the screen just for testing purposes. I tried it with pgaccess but it doesn't seem to be unicode enabled.
Many thanks for your help.
Anton

// Anton Güntsch
// Botanic Garden and Botanical Museum Berlin Dahlem,
// Dept. of Biodiversity Informatics
// Königin-Luise-Str. 6-8, D-14191 Berlin
// Phone: +49-30 / 83850-166 Fax: +49-30 / 841729-55
// Email: a(dot)guentsch(at)bgbm(dot)org
// URL: http://www.bgbm.org/guentsch/