I am trying to create a basic custom list that will have a column labeled "Products needed for training" it should be able to accept multiple entries but still be linked to the overall training event (the title column)
You want to create a taxonomy field (Managed metadata), this will allow a look-up via a UI and a as you type look-up. You can make it a folksonomy using Enterprise keywords (Where a user can define their own) or fixed using taxonomy and Managed Metadata and allow multiple values and select your term set (Upload to the site collection first or create manually). Please refer to this link for more information. http://technet.microsoft.com/en-us/library/ee424402.aspx
There are four sharepoint list columns that will allow multiple entries:
- Managed Metadata
Obviously, persons would not be appropriate for this scenario. But the other three can all work.
- Choice is good if you have a small amount of products.
- Lookup is good if you have a separate list for the products needed for training.
- Managed metadata is good if you have complicated hierarchical products for the training. There are also other reasons why managed metadata would be beneficial, but more details will be needed before an educated decision can be made. Managed metadata is probably the most scalable in the grand scheme of things.