Setting up two clusters, Help required

I need to setup two clusters, Cluster1 and cluster2

Both having databases, DB1 and DB2 respectively

And i need to setup database replication among both DBs, i-e if value in table1 is updated in DB1 then it will update same value in table1 of DB2

for this purpose i have installed ubuntu server. But don't know how to proceed further.

Step by step guidance will be much appreciated

This may be helpful to you => http://www.howtoforge.com/how-to-set-up-database-replication-in-mysql-on-ubuntu-9.10

I already went there, but firstly i need to setup two clusters