Also, you stated:
"only have a few hrs in this make and model"
You don't have any info in your profile - if you are a Cessna driver converting to Piper for the first time (i.e first time really going to be on your own and acting real PIC), then you need to take the typical cautions.
#1 - Fuel Management - there is no "both" on Pipers. On X-C's you either think in terms of each hour/half-hour of flight and make mental notes to change tanks or you find out the hard way.
#2 - you have to do a lot of "s" turns to look down. Cessna drivers think that not having that wing above their head is quite liberating but they forget that you can't look down through all that sheet metal in the wings. Ya' gotta make s-turns to see what might cause problems below.
#3 - "flair" in a piper is how you act at the FBO. Putting huge elevator corrections for a flair a'la a Cessna-172 haul back on the yoke is just gonna cause quite a ballooning effect. Just lift the nose of the Piper so that the little hump for the prop just touches the end of the runway in your sight lines and it will "auto-land" every time.
#4 - carb heat - oh never mind you're in a Arrow. However, there is the great debate about its use in Piper carb equipped aircraft.
#5 - Performance tables and the use of magnifying glasses. Why Piper couldn't just make tables like Cessna, but anyway do some study and follow the magic dotted line in the sample.
#6 - Do not lock Piper cargo doors. In an emergency and turned the wrong way, you have only one escape door out of a Piper unless you leave the cargo door unlocked. If it is unlocked, you take your fuel sampler with the phillips head on the end and remove the two screws on the back of the door. Push the spring aside and the cargo door will pop open. If locked, you won't get it open until somebody puts the key in the outside. And to all those who want to kick out the plexiglass, if your plane has the .40 plexiglass instead of the .25 you can be kicking pretty hard trying to make a crack!
#7 - push the flaps down on a pre-flight, there's a spring in there so that you can look at the bolts holding the flap on. When pushing on the flaps or ailerons do so only at rivet lines - the plexiglas may be thick but the aluminum is pretty thin. Don't put greasy fingers on the wing-tip strobes (look but don't touch) the heat from the strobe boils the oil residue from your fingers and breaks the glass. The pitot tube has three holes, pitot, static and a drain - all need to be clear. Piper stall vanes are tested by lifting the vane slowly until the horn sounds - do not just pound the switch to the top and listen to the horn - the horn should sound before the vane hits the stop. Never squeeze or rub the "royalite"(plastic) wing tip and elevator fairings. That stuff is very brittle in the sun - I have all fiberglass and composite parts now on my Cherokee. When you are inspecting the horizontal stabilator, get on one end like the stabilator is a see-saw plank and lift gently and press gently - if there is a "click-click" noise, I suggest you get the bushings replaced pronto - there have been binding problems on all the PA28's. Last pre-flight item may actually be your first on the checklist, depending on the year, there are pitot-static drain buttons on the fuselage wall (inside) next to the pilot's seat - make sure you push these buttons in once a day (first flight) to get any water out of the lines.
The most dangerous items for you are fuel management and that Piper "lock-out" mechanism on the free-fall gear. As the previous post said, you use it on the short field takeoff and then forget about it on your next landing and well it could be a long time before you take off again. If the "lock-out" is not disabled on your airplane, make it part of your GUMPSS flow to check that lockout button. And I know you're thinking 3-green, gear warn horn, how the heck can I make a stupid mistake - yeah, ask that of the people who land at dusk (nav lights on) with a broken gear horn wire.
Did we mention the "nav light" wash out? - with nav lights on in anything other than real night time, the 3-green are almost invisible - favorite CFI trick is to turn the nav light switch on during the day and see if the student will land without seeing 3-green.
Finally as noted above, starting the fuel injected Arrow on a "hot" start can be exasperating. The vapor lock is tremendous. What I like to teach people is to think of a straw or better yet siphoning fuel out of a gas tank using a piece of hose. If you get a bubble of air in the straw or the siphon hose, you make a real mess out of your mouth and nostrils (Coca-cola or gasoline). You want a continuous flow of fuel to the injectors until the engine starts. With that - on a hot start - mixture lean, throttle open about a half inch, crank the engine, while you flip the fuel pump switch on, then while continuously cranking move the mixture forward - that should keep a steady flow of fuel without creating a vapor lock. (Note: the difference between this and the book is I am cranking the engine before the fuel pump goes on, this stops fuel being pumped to the spider before you are ready for it.) That works on 90% of the starts - if you flood it, reverse the throttle and mixture controls - open the throttle all the way and shut the mixture off until you get some kind of a cough of ignition. The arrow starts beautiful when cold but is a beast when hot.
Problem is worse when the engine is hot; if you do, procedure is to start cranking again with the mixture all the way out, then richen again as the engine catches. Only a little throttle is needed to put enough gas in to get it going - maybe 1/2 inch or so. 
