Hi Ben,
Congrats on the new 8-tracker. I can give you some pointers and others will add as well, I'm sure.
For starters, stay away from used tape from EBay. A large number of older tapes (Ampex in particular) have developed what is called 'sticky shed' over the years.
This condition causes the tape to shed itself all over the tape machine's heads and transport, requiring lots of cleaning and loss of your recording.
Trust me, it's worth the money to buy new tape. You don't want to experience sticky shed. I have had it happen once, just a little, when I transferred an old reel and that was enough for me.
Here's new tape for you:
http://www.totalmedia.com/catalog/catalog_home.asp?CatID=1633&OID=-1&CID=&bustype=01
Next you need a demagnitizer, to keep your tape path non-magnetic (so it doesn't start to do a subtle erasure of your tape.)
The best ever made, and the industry standard for reel-to-reel is the Han-D-Mag by RB Ennis:
http://www.usrecordingmedia.com/handmagdebyr.html
(US Recording also sells tape, so you can compare prices.)
NOTE: when I say the "Mag" blows everything else away, I am only half kidding. It is a very powerful instrument that, if used wrong, can damage your tape recorder or surrounding electronics, so if you get one, USE IT EXACTLY AS THE MANUAL SAYS.
For additional money you can get a little round mag-meter with the unit. It will show you if demagging is needed; very convenient.
To set the machine up, you can either pay a tech to do it, or buy a calibration tape (by MRL) and learn to do it yourself.
Calibration tape:
http://www.usrecordingmedia.com/ancaltap1.html
Cleaning is crucial. I use Caig Caikleen for pinch roller conditioning and find it works very well:
http://store.caig.com/s.nl/sc.2/category.179/.f
For head and tape path cleaning, I use 99% isopropyl alcohol from CVS or a similar store (don't use a lower concentration than that, and make sure you get the pure alcohol.)
Chamois cloth is great for cleaning the tape path; get a piece cheaply from a sewing/materials shop and cut a piece to use when needed.
Finally, a bulk eraser is a good idea. It is basically a big electrical magnet that wipes tapes cleaner than the erase head on the machine can do.
I got mine on EBay; look there, and make sure the model can accept 10-inch reels (a 1/4-inch tape model I believe should work for you, but of course it would be ideal if you could locate one that is made for 1/2-inch tape like you use.)
I'll see if I can find the listing for editing supplies; there's a company that stocks pretty much all of that.
The things I have recommended do cost some money, but, as always, you get what you pay for.
You said you are brand new to tape, so a few things:
Always store recorded reels 'tails out'; in other words, wind the tape to the tail end and store it on the take-up reel. The reason: with storage, recorded sounds can 'print through' to the tape layer below, so you'd get a faint 'pre-echo' just before the song starts. With the reel tails out, the echo would now be at the end of the song instead, so, easier to deal with.
Always store tapes standing up, in a cool, dry-ish place.
That's about what I can think of right now; I hope this will be useful to you.
Have fun with the new machine, and good luck.
Best,
C.