The Backup plan is entirely dependent on what type of environment your are running. Lets assume it's a MS SQL server, since it's Server2008 and Exchange 2010 in the tags. Info on choosing a strategy: Back Up and Restore of SQL Server Databases
Info on Transactionlogs backups: Transaction Log Backups
A typical set-up would be a Full Backup, as is now, at 8PM and schedule Transactionlogs backups during the day, depending on if RPO or RTO is more important. Info on RPO/RTO: wikibon.org/wiki/v/Defining_RPO_and_RTO
Keep in mind that when u do transactionlogs and only a full backup in the morning, when the data needs to be restored, you need to start with the full backup and then restore each transactionlog backup, since the transactionlog backup only contains the changes since the last backup. The RTO will be high.
If downtime is an issue, take full backups more often and keep doing transactionlog backups in between. If the database isn't too big so that backups take to long
Again, it's totally dependent on the type of environment you are running and what is agreed upon in SLA's if any.