I would like to check some messages deleted on my phone, but on my bill...can I go online to see them?
You can view your past 90 days worth of message logs through your MyVerizon account online, but you can't see the contents of the messages unless you had previously setup Verizon Messages for that line.
How do you do that?
If you backed up your Messages onto your Verizon Cloud you can log into it online and view them that way. If you use integrated messaging they automatically get backed up, but are only there for 90 days.