The phrase "a guide to where" is correct and usable in written English.
It can be used when referring to a resource or document that provides direction or information about a specific location or destination.
Example: "This book serves as a guide to where the best hiking trails are located in the national park."
Alternatives: "a resource for locating" or "a reference for where".
Here's a guide to where things stand ahead of Monday's hearing.
The Institute for Government has produced a guide to where civil servants are to be found across the UK.
THE 2012 Mercedes-Benz CLS, which will be introduced at the Paris auto show in October, offers a guide to where the company's vehicle designs are going.
SP Various BBC Jazz Awards 2006 (Specific Jazz) £7.99 As a guide to where contemporary British jazz stands right now, this double album is unbeatable.
The map can be a guide to where to dig and a framework in which to plot discoveries and thereby give shape to the past.
Think of Wikipedia, or of ranking systems at places like Yelp and TripAdvisor, which let you use the collective judgment of travellers and diners as a guide to where to eat and where to stay.
The prices, so often a reasonable guide to where a dish should sit in a meal, rise and fall like waves on a stormy sea: from £9.50 then up to £16.50, back down to £10.75 then up to £21.75.
Shoes – often a useful guide to where a season will sit on the grunge to glamour scale – are typically an elegant but low-heeled sandal, in a neutral colour.
More recently, researchers have shown that the ratio of isotopes in feathers can provide a rough guide to where a bird has been feeding, because the feather ratios mirror those of food sources.
There has never been a better time to buy a phone, so here's a quick guide to where to put your money.
Placeopedia tackles the problem with Wikipedia of not having a visual guide to where (in a map) articles refer to.
