Whether to brush or roll stain on wood depends on the project and your preference. Brushing is ideal for smaller, intricate areas and offers more control over the application, ensuring thorough coverage and penetration into the wood's grain. 

Conversely, rolling is efficient for more extensive, flat surfaces and can save time. However, it is not always the best fit for textured or uneven wood. Some projects may benefit from combining both methods, using a brush for detail work and a roller for broader areas. Ultimately, the choice between brushing and rolling depends on the specific requirements of your staining project.

Routine cleaning, sealing/staining, and inspection prolong deck life and appearance.

It is definitely worth sanding a deck to ensure the wood absorbs new stain. Sanding a deck removes the outer layers of aging wood, allowing the stain to penetrate. It also gives a fresh look to the entire surface as part of the deck refinishing process. Without sanding, your stain or sealant is less likely to absorb into the wood. While sanding a deck is a time-intensive project, the rewards are noticeable and long-lasting.

Yes, beginners can use a paint sprayer, but there is a learning curve. It's important to go slowly, read the instructions thoroughly, and spend some time learning the technique. Watching tutorial videos for your specific paint sprayer model can be very helpful. Before starting your main project, practice on a scrap surface to get used to the sprayer and avoid common issues like overspraying, which can cause drips, bubbles, and other imperfections. For safety, always wear a mask and gloves, and be careful not to touch the sprayer's tip when it's in use, particularly with high-powered airless sprayers.