Belarus has a thin travel literature tradition in English, but the country has produced writers and thinkers worth knowing before you go.
Secondhand Time by Svetlana Alexievich (2013) — Alexievich, a Belarusian journalist and Nobel laureate, collected oral testimonies from ordinary Soviet citizens about the collapse of the USSR and what came after. Not specifically about Belarus, but essential for understanding the world your hosts grew up in. Her earlier books — Zinky Boys (on the Afghan War), Voices from Chernobyl, and The Unwomanly Face of War — are equally powerful.
The Bronski House by Philip Marsden (1995) — A quiet, melancholic journey through the Polish-Belarusian borderlands, tracing the faded traces of an aristocratic family and the landscapes that swallowed them. One of the few good pieces of travel writing from this part of the world.
Belarus at the Crossroads edited by Sherman W. Garnett and Robert Legvold — A collection of essays on Belarus's political situation after independence, aimed at a policy-minded audience but readable for the background it provides.
The Last Country and reporting by Hanna Liubakova, Franak Viacorka, and others at Radio Free Europe — for current, on-the-ground journalism about what's actually happening in Belarus, the English-language output from Belarusian diaspora journalists is better than most books. Follow them online.
For guidebooks, the Lonely Planet Russia & Belarus edition (out of print but second-hand copies exist) remains useful for practical orientation even if the political chapters are outdated.