Hawg View

Hawg View is a website primarily used for aerial operations, but it can also be utilized to create OPORD-related symbols and graphics. Looking at the picture to the left, you can see how there's key information presented for the graphical depiction of OPORDs and CONOPS. This is an excellent tool for creating CONOPS / OPORD preparation.

Battle Staff Tools

Battle Staff Tools, much like Hawg View, allows you to create custom NATO Symbols and Graphics for your OPORD and CONOP briefs. You can customize the entire symbol and create unique Order of Battles for OPORDs. FM 1-02.2, Military Symbols, is integrated into this website, allowing you to refer to it at any time for assistance.

FM 1-02.2

FM 1-02.2 Military Symbols is one of the main things you will need to look at for OPORD / CONOP Graphics. As it is built into Battle Staff Tools, you may not need to refer to the FM. However, when in a pinch, this can be of assistance.

TC 3-21.76 - Ranger Handbook

The Ranger Handbook is the holy grail of information for any operation. If you want to find any quick refernece or information regarding something, rest assured it is in there. Some common places and information to look are:
2-1 - Troop Leading Procedures
Chapter 7 - Patrols
Chapter 8 - Battle Drills