How do I get posts of a content type on node writing I have three content types: endorse, deals, and recommends. Recommends has three nodes.

How do I show those three nodes from the recommend content type on the deals content type using a field on the deals content type writing panel?
You can use the References Module, that can be used as a node reference of any other content type. After installing the module, go to deals content type manage fields, select the node reference to field to recommends content type and while configuring field make it as unlimited, and now go to deals content type writing panel, here you can see the multiple field and can access the node id or name of the references content type nodes.
You can list the selected nodes of references under deals node in views using relationship.