When I import a CD to itunes, it splits the album in to multiple entries. I have changed the info on some but others just will not merge. Is there an easy way to do this and can I stop them from splitting in future? Thanks

Same problem here.

iTunes will group tracks into a common album if:

• all songs have the same Artist value and the same Album value, or
• all songs have the same Album Artist value and the same Album value, or
• all songs have the same Album value and the "Album is a compilation ..." flag is checked.

There do seem to be cases (starting from iTunes 12.0, as far as I recall) when grouping is not evaluated correctly even when one or more of these rules is satisfied. This can normally be addressed as follows:

• select all songs that should be part of a common album
• edit the Album field and insert a "dummy" character at the start - e.g., change "Dark Side of the Moon" to "xDark Side of the Moon"
• the songs should now group correctly
• repeat the edit operation to remove the dummy character - the album grouping should be retained.