The quickest and easiest way to maintain your wooden objects over time is to treat them with primer. Good quality items are generally already treated with an impregnating base, which means you can leave them in the open air for some years without problems.
Every 2-3 years, however, you will need to repeat the process of treatment, to keep the wood healthy. First of all give the article a quick cleaning, using a microfibre cloth; then sand down all the wood, so as to remove impurities and smooth the surface.
At this point you should give it a first coat of primer: it is often produced in a very fluid state, so be careful not to drip the product. Also avoid using too much or too little.
Wait for the first coat to dry, and repeat the process of sanding. At this point, apply a second coat of primer, again making sure to apply it correctly. If you have excess left at the end, pass a dry brush over the entire surface area,which will remove the excess.