Just in case, you can download the playtest book from the Paizo site itself. {these is a PDF download on the main Playtest page,-just hit 'Playtest' from the Pathfinder and your there- free for everyone.)
Or if the missing book in question is the one outlining Kitsune from PF1, all the main info can be found in the Pathfinder Referance Document on the site as well, under "Uncommon Races" in the Advance Race Guide.
As for building the race, if your group is running the playtest in earnest, {giving feedback and such}, I would suggest against it. The point of the playtest is to see how well everything runs for this new version, what people like, what people didn't, possible problems, possible things to expand on, ect. Adding a homebrew element {even a small one} can change how the game plays, and how useful the feedback is because of it {ie you have a problem not seen in other games due to the new element, or that new element fixed a problem in game before it started, but because the problem was never encountered, its never reported, and therefore never adderessed in the final product.
If your group is not planning to give feedback, then I would suggest reading the race enteries the races both from PF1 and the playtest, and see how the changes were made, using it as a rough base. {ie races no longer get every single ability from the start, nor will they have every single one by the end. There is no race that has more then 10 feats to choose from, and 2 feats invovle racial weapons {one for Prof, and one for Speicalzation} Also remember every single +1 is more powerful in this edition then pervious. Basically the race will start with a base speed {remember the average speed in the playtest is 25feet vs the 30feet in PF1) langauges {normally common and a racial one} and a set of bonus langaues for high Int, vision, and racial stat mods {if you are following the PF1 versions of kitsune, they would most likley have +2 to Dex and Cha, and a -2 to Str, along with a free +2 to a stat not already bumped by this choosen during charater creation.)
Above all else, talk with your group to see if this is ok. At the end of the day, no mater what, you need to get there ok with the final product if you are going to play with them, with this. Get them invovled in the building process of the race, no one whats to be overshadowed by an overpowered character, espeically if that charater was not avaibile to them, or if it makes there own by the books charater concept seem invaild by comparasion. But on the same hand, everyone whats to stand side by side with a capable one. Listen to feedback, and concerns, escpally if your firends have already started playing, they will have a little bit better understanding of how everything fits, and the blance between Power, Fairness and Fun. And, if you do end up playing it, be willing to change it if the group starts having problems with it in pratice, and on the same hand, if you have problems with it yourself be willing to adress that to the group to see if there is a fair soultion to it {bascially, playtest your own homebrew :p }
