Step by step SharePoint migration

Steps to migrate one moss server to other server
1. Take back up of all databases from SQL management studio (in .bak format)
2. You can also copy the .mdf and .ldf files of the content databases
3. Must remember the versions of the databases.
4. Copy the backed up files to some safe location
5. Create a new MOSS server
5.1 Install .NET 3.0 or later version
5.2 Install SQL Server 2005 or later version with SQL management studio
5.3 Install MOSS
6. Do not run PSconfig after installation of MOSS
7. Before that we have to copy the backed up databases files to the new server
8. Restored the databases form the .bak files to the newly installed SQL server
9. You can attach .mdf files to the new databases.
10. After copying the backed up data to the newly created MOSS machine run PSConfig wizard
11. In PSConfig wizard if you want the same customization as it was in the previous one then connect the MOSS to the existing farm and in the existing farm select the old configuration database.
12. Wait till the PSConfig wizard will be completed.
13. Open the Central admin page and check whether you get the same customization or not.

Now how to up your previous sites back in to the new MOSS machine.
1. Create a new site in new MOSS machine
2. Go to the content databases option in Application management of the central admin page.
3. Dropped the existing database , now your site comes down
4. Open the command prompt and type the following command to attach the content DB of the previous machine

Stsadm –o addcontentdb –url -databasename

5. The database which you want to attach must be restored in the SQL server