I cooked with the 105 for around 5 years and always added wood at the beginning. Sounds like you might be starting out with the oven. If so, the following may be of help:
Learn to cook with only one kind of meat in the smoker at a time. Once you get the hang of things, you can mix things up with some experience under your belt.
Do only timed cooks with no hold time. Use only one kind of wood, oak is forgiving and pretty common. I typically used fist-sized chunks, and the bin was 75% - 100% full, varied by your results and taste.
Some people add one lump of charcoal to the bin to add a little "color".
I would limit learning to no more than two kinds of meat, ribs (hut in half racks) and whole chicken. These cook faster than turkey, pork butts or brisket. If you must cook pork butts, cut a boneless butt into 4 similar size pieces. They should cook in a similar amount of time as ribs.
Cook with a thermometer/probe in the meat, with monitor outside of cabinet.
Formulate a process and don't deviate much. Add meat to smoker at consistent time (ie when oven is cold or hot). Place meat in smoker that is of a consistent temperature (ie cold vs room temp) Keep a journal of your cooks, consistently evaluating characteristics such as juiciness, smoke flavor, smoke intensity, color, length of cook time, where meats were placed in the cabinet, ambient temperature.
It took me a while to learn how to use the oven, but once I did, it was used to cook turkeys. Typically two at a time. I thought the oven retained moisture pretty well.
I'm probably forgetting some stuff, feel free to PM me if you like. Before selling the smoker, I took photos of my journal and the things I evaluated.
As mentioned previously, keep it simple until you get the hang of things. The learning process will be shortened by varying no more than two variables per cook.
Good luck!
