Custom fields and downloading.

Hi, I'm farely new to omeka. I'm working to create a library with accessabel content for people with disabilities. There's a list of fields for collections and items in the collections. I was wondering if there is a way to add my own field to replace the ones that is there and how can I go about doing it. also the next thing I want to do is have an option to upload the digital content where it can have a link to the item for download.

I forgot to specify that it's using the dublin core. I don't want to use the fields from the doublin core. I want to use some of them but delete some and add my own.

You don't have to use all of the Dublin Core metadata fields - the empty ones won't display unless you want them to.

If you want custom fields for items, you could create custom item types for the content you're working with.