Instead of manually scanning for values every time (which is tedious for gold and stats), you can use pre-made Cheat Tables (.CT files). Here are the most reliable scripts for Hellfire.
Look at a value you want to change (e.g., your Gold amount). diablo hellfire cheat engine
If you are doing a manual scan, use and 4 Bytes . For Gold, search your current gold, drop one piece, search the new value. For stats, it is easier to use the Character Panel (C key). Instead of manually scanning for values every time