Creating a door legend is a fairly simple task. To start out, create a Legend from the View|Create|Legend ribbon. Specify a name and scale for the drawing (you can adjust these later).
After the legend is created, you are presented with a completely blank screen and your new door legend shows up in the Project Browser under 'Legends'. The great thing about this legend is you place graphical representations of families or elements in your model. For this example we will be placing elevation views of the door families in our model. The elevations which show up are exact parametric representations of the doors which are in the project. They are exactly similar to what appear in elevations and sections and if you change the door family, the legend will update automatically, so why do it any other way? Creating legends can also be useful for other tasks, such as a symbol legend for your RCP's, or furniture plans.
To go about placing the legend components, go to Annotate|Detail|Compenent and select Legend Component.
Your property toolbar now appears with a drop down list of all the families located in the project organized by category. You want to select your door family, then for view, select elevation:Front. Click in your work area and Revit will place the front elevation of your door.
Typically we create different Legends for the frame types and for the door types. We can easily accomplish this by using the visibility graphics and sub-categories. Note: This will only work if your families contain sub-categories. If you created the family on your own you will need to have defined sub-categories for all the components of the family. If you used an out of the box template to create your custom door, then the sub-categories are already there, all you need to do is assign them to your solids.
This first legend we will create will serve as our frame types. Go ahead and place a couple more door families in the legend so we have a couple. One fallback to using this method is that if you imported a door family to be inserted into a curtain wall, that door will not show up correctly in this legend since it's properties are not set by the type properties of the family, but rather the instance properties of the family (which is sucks from the curtain wall). After placing a couple more doors, open up your visibility graphics and expand the 'doors' category.
Notice how there are several sub-categories listed here including several listed as 'Panel' and 'Frame'. Since we wish this particular legend to be our frame schedule, uncheck all the 'Panel' sub-categories, as well as the 'Elevation Swing' Sub-category and hit 'OK'. On your screen you will now see just the frames left over.
Since these are live Model Elements, you can go ahead and use tags as well as dimensions on them. Add text notes and dimensions as necessary to convey all the information you need to (sizes, types, etc.) and your legend is now finished! If you change any of these families in your model, they will change in this legend too!
To create a door panel legend, simply duplicate this legend (from your project browser), open up visibility graphics, check the 'panel' sub-categories that we previously unchecked and uncheck the 'frame' sub-categories.
Easy and parametric! Gotta love it! Now you never have to worry about your legend differing from your plans, sections or elevations!