Series One contains 112 cards - 73 "regular" player cards, 22 Title Holder cards, 13 "Memorial" cards and four checklist cards. (There are also 24 "Star" cards which are considered premium insert cards and were not included in the set I got).
The 73 "regular" player cards are really 72 "regular" player cards plus a card of Swallows manager Junji Ogawa which I will discuss more in a minute. The 72 player cards break down to 6 players per team. It's hard to complain about player selection in the set since there will be two later Series that will include other players (I actually considered waiting until all three Series were out before reviewing the set). So it's silly to complain that Matt Murton (for example) isn't in this set when he'll probably be in one of the other Series. I did find it interesting the difference between the way the two teams that significantly changed their uniforms (the Dragons and Baystars) were treated in the set. For the Dragons, all the cards show the player's in last year's uniform except the card of Takeshi Yamasaki, who was an Eagle last year. For the Baystars, however, everyone is shown in the new uniform. I suspect this is because the Baystars changed ownership and name as well as uniform.
The photography is, as always, outstanding. Here's a couple examples:
The "Title Holder" subset is essentially Calbee's version of BBM's "Leader" subset. Instead of issuing a card per statistical category like BBM does, Calbee issues a card per player who leads in at least one category. For example, in this year's BBM 1st Version set, Seiichi Uchikawa has two Leader cards - one for the PL MVP award and one for the PL batting crown. He only has one card in the Calbee subset (#T-01):
In case you're wondering, the only guys who have cards in BBM's Leader subset who are not in Calbee's Title Holder subset are Koji Akiyama (Shoriki Award) and Takahiro Shiomi (Rookie Special Award). BBM's Leader subset card for DJ Houlton shows him as member of the Hawks (his 2011 team) while Calbee's Title Holder subset card has him as a Giant (his 2012 team).
The four checklist cards for Series One show scenes from either the 2011 post season or late in the 2011 season - the Hawks celebrating their Nippon Series championship, the Dragons celebrating winning the Central League and the Swallows celebrating advancing in the playoffs and something (not sure what) with the Fighters and Atsunori Inaba from mid-September. Here's the Dragons' celebration card (card #C-2):
You can see all the cards here (along with the "Star" cards here).
UPDATE - did a little research on YakyuBaka - the Fighters game from the checklist was last September 13 against Lotte. Inaba hit two home runs in the game, leading Nippon Ham to a 4-0 victory.