A few things I've noticed while doing research of players from bygone eras:
1) Most of the best descriptions of a player's playing style, strong and weak points come from the first few years of his peak, when the information is still "news". This is true of modern players, as well. Nobody spilled a lot of ink describing Gretzky's still amazing post-Edmonton play because everyone knew by that point what a great player he was.
2) Playoff games tend to yield better, more granular descriptions of player performance than do regular season game reports, which almost always gloss over the game action and list only the scorers. If you're going through old periodicals looking for information beyond mere scoring stats, start with the playoffs before you go to the regular season. Searching in the appropriate date ranges (generally March and April for prewar guys) can save you a lot of time.
3) Don't include words like "hockey" or "playoffs" or Stanley Cup" in Google archives searches, as they will filter out articles where these words are not mentioned or not correctly read by the scanner. Search for the full name (or common nickname - like Ching Johnson) is generally your best bet. Only use the "hockey" tag if your player has a common name and you want to avoid non-hockey related articles, but be aware that you will miss some hockey-related stuff, as well.