Tried and tested tools, shops and services. We only recommend what we actually used and liked.

If you like playing games or even making them, take a look at a list of places to buy games and nice tools we use for game-making. Some of them are free, others very affordable. We have been using some of the things on this list for years, others for months, but they all serve their purpose very well.
Buying Games:

Play-Asia - online shop specializing in Japanese Video Games for Consoles and PC.
They have a great selection and we buy most of our DS games there. You can find Princess Maker, Angelique and similar series, as well as some less known titles (such as MTO's cooking games). Most games are in Japanese, but some English versions are also available. (The Phoenix Wright series, for example, contains both versions on one cartridge). Play-Asia often has better prices than Amazon, especially for older games.

Making Games:

Ren'Py - visual novel engine
Ren'Py is a free and cross-platform visual novel engine that we used to make The Stolen Diamond Ring. It's well structured, easy to use, very customizable and really makes it possible for non-programmers to make visual novels. Not only is it well maintained and supported by its developer, it also has a reasonable, polite, helpful community - if you have a Ren'Py related question, someone on Lemma Soft Forums probably has the answer and they won't insult you in the process.
Highly recommended!

How to Draw Manga Volume 5
"How to Draw Manga" series is one of the best resources for producing Japanese-style graphics, but it can be difficult to decide which book to buy - there are so many!
Volume 5 (Developing Shoujo Manga Techniques) might look somewhat outdated and shoujo-centric, but it's actually one of the best all-purpose books in the series. It covers everything from facial expressions and basic perspective to plotting the story. Most of the information found in this book can be applied not only to any kind of manga but also to visual novels. Great advice for beginners.

sfxr - sound effects tool
sfxr is a small (100 kb + a few extra files), free tool for generating randomized 8-bit sounding audio effects (jump, damage sounds, various blips for interfaces etc) by simply clicking a few buttons. The .wav files it exports seem to be somewhat corrupted (for example, Winamp and Windows Media Player can't play them), but this can be remedied by importing them in Audacity or similar software and reexporting.
All the sound effects in ButaVX were done in sfxr.