Tourism infrastructure in and around Coban is lacking a lot... especially if you're on the $2 a day travel plan. There are some nicer hotels but even they sometimes are subject to rooms that let in noise or light from the streets, etc. These are some tips for Coban travel:
1.) Bring or buy some meds to help with nausea on the winding roads. A friend of mine used her allergy medicine from the US that made her drowsy on long trips. I bought a pill called Nauseol from a small pharmacy and took only half which was enough to make me sleep for the first 1.5 hours of the trip to Coban and kept the nausea from setting in through the whole trip. The two previous trips to/from Coban that I did not use meds for this, once I was able to hold my food down but not without nausea and the other time I threw up into a plastic bag... So if you don't want the meds, make sure you bring a bag.
2.) Bring ear plugs since this can be a noisy little town when you're trying to get some sleep. When it's not pouring rain on the tin roof the dogs in town are howling at each other and the traffic outside is probably very audible from your not-insulated hotel/hostel room and just when the night noise settles down, the roosters start to crow at about 3am. and on holidays (or even peoples birthdays) the locals love to set off fireworks at 6 in the morning. So do yourself a favor and bring some earplugs. They are also useful on the Monja Blanca bus if the driver is blasting what he thinks is nice music.
3.) Might as well bring an eye mask just in case.
4.) INSECT REPELLENT. Do not forget this and don't bother trying the natural stuff, it's like spaghetti sauce to these mosquitos. Bring something with DEET in it. There is a good anti-itch balm sold in some pharmacies here called "Sana Sana". Rub it on bites you already have to calm the itch.
5.) A good but compact umbrella is imperative. Don't trust that blue sky in the morning because knowing Coban by 3pm the whole sky will turn an ominous dark grey before it opens up and pours buckets. Hey, it's not a tropical forest area for nothing.
6.) Be careful what you eat and drink here. In some places street food is an indispensable part of the local experience, in Coban it will lead you to diarrhea 8 times out of 10. So stick to your guest house, reputable restaurants, or preparing food that you bought at the market for yourself. If you can't resist the tayuyos or the greasy fried tacos, then ask a local that you trust where is a safe (read hygienic) place to buy them.
7.) Remember that you are in a place where the vast majority of people have a lot less than you have. There are many wonderful kind people here, but there are also those who see it as your fault if you pull out your iphone to look up an address on the street corner and have some kid snatch it out of your hand. If you need to use your cell phone (especially if it's a nice phone), use it at the restaurant or somewhere private (private but not deserted). And in general just be careful with your belongings. Keeping valuables in an outside pocket of your backpack is also not a good idea.
8.) Be careful on the streets in Coban because drivers will always take the right of way and most of them will not stop to see if you are okay after they hit you. It's just the way people drive here for now, so always look both ways before you cross the street.
9.) With all that said, do try to mingle and talk to locals as much as you can. You don't want to end up learning more about your Dutch or Korean fellow travelers than you do about the local culture. Don't be afraid to USE your Spanish or pick up some words in Kekchi while you're here. Have a great time and treat yourself to a more expensive restaurant or hotel once in a while when you need it.