Instructions
Getting Into Grid Mode
Open your copy of RPG Maker 2003.
Open the project on which you want to work. If this project is already open, then skip this step. If you have no projects to open, click on the icon that looks like a blank piece of paper near the top left of the RPG Maker 2003 window (if you hover over this icon a caption that reads "Create a new project" will appear) to start a new project.
Click on the icon that looks like a mouse pointer hovering over a yellow frame. If you hover over this button, a caption will appear that reads "Edit the event layer (F7)." This will put you into the event editing mode, or grid mode.
What to Do When in Grid Mode
Right-click on one of the squares of the map that you have open for editing. This will open up a menu of options.
Choose the menu option for the event that you want to create. You can create a new event from here (click on "New Event"), create a teleport event (to move from one map to another, click on "Place Teleport Event"), or create a party or vehicle start position on your map (click on either "Place Party Starting Position" or "Place Vehicle Starting Position").
Create your event from the commands available from the "Event Commands" menu, if you clicked on "New Event." You can access this menu by double-clicking on the event commands field (the white space in the window that appears after you click on "New Event").