The best thing you can do is to learn some Spanish. Obviously speaking the language helps anywhere, but in Guatemala it’s more or less essential if you want to gain any real sense of the place at all. It’s not one of those countries where hello and thank you will earn you gasps of amazement and invitations to family dinners. Unless you can at least hold a basic conversation you’ll be dismissed as just another ignorant gringo, and scorned and ripped off accordingly.
Luckily, if you don’t already know any, Guatemala’s the perfect place to learn. There are Spanish schools all over the place, which are among the cheapest in Latin America. In rural areas a few phrases in one of the Mayan languages can earn you some major brownie points, but make sure you’re using the right one for the place you’re in because there are 21 dialects and they’re all really quite different.
Guatemala is a tease. It lures you in with promises, then goes all shy and hides its best bits. The Mayan culture, which for most people is the country’s principle attraction, is only properly seen in the villages. Look on a map, pick any little dot with a ridiculous number of syllables and an ango/ingo in its name, and go there. It might surprise you.
Guatemala is pretty cheap to travel but it does have a strong drinking culture, and you may find a disturbing percentage of your budget going on alcohol. One way of dealing with this, short of doing something crazy like drinking less, is to teach yourself to like Quetzalteca. This is the truly bog-standard Guatemalan rum and may well be a toxic hazard, but it has the advantage of being cheap, extremely potent, and so disgusting you’re unlikely to want to drink more than is strictly necessary.
Choose your destination carefully over the Semana Santa (Easter) period, as all the more touristy areas get pretty manic. Which can be fun if you’re in the mood, but accommodation prices shoot up and watching drunk people shout and vomit gets tiring by the end of the week. The worst places are Antigua (for the former) and San Pedro Atitlan (for the latter). If you’re working, on the other hand, this is your best time to make some quick cash. Paste on your most charming smile and watch the tips roll in. Same goes for if you’re selling artisania. Make an extra load beforehand and give your prices a hike. Hey, if everyone else is profiting shamelessly from their saviour’s gruesome torture and death then why shouldn’t you?