To create a new project you need to go to Redmine tab at the Outlook ribbon and press a Project button.
After that will be opened window to creating project (see screenshot below).
Fill the fields you need and press 'Close' button to saving this project.
Create a subproject
Also you can automatically added a chosen you project into Project field of creating project.
To do this just select a project you need and then click the Project button.
Create a project from email
Right-click an email that you need and and select 'Convert into Redmine' -> 'Project' from the context menu.
After that will be opened a 'Create Project' window with email you choose into description field:
Fields of the 'Create Project' window:
Description
A short description of the project.
Public
The present project will be public and everyone can see this project and may do things that are allowed by the roles Non member and Anonymous. Non-public projects can be viewed only by a user who was given access by an administrator of the project.
Identifier
URL prefix, by which creating project will be available. Once saved, the identifier cannot be changed.
Parent
The project that will be parent for creating project.
If you want to create a child project of the existing project you should select the project which should be a parent for the new project and then press the Project button in the Redmine tab at the Outlook ribbon.
Inherit members
Allow inherit members from parent project.
Trackers
Select issue trackers of the project.
Modules
This list lets you choose the modules you want to use for the issues of this project.
Choose users that you need and click 'Add' button. Selected users will be added to the project.