Well.... kinda depends on how far you need / want to go.
Ways to find information:
www.google.com
example search:"
downloadable factory service manual site:ih8mud.com <100 series> "=>
#1 result
^^^ download that
Part sources I use:
www.partsouq.com (OEM parts from UAE, also a good place to find part numbers, deals are hit or miss and sometime absorbed by shipping)
Example - front brake pads for an 05 LX470 are P/N 04465-60230
Search by P/N on Google Shopping, eBay and Amazon to compare prices. Bell Lexus on eBay is a favorite of mine, but there are lots of options.
Searching that part number gives you a range of options.
Here is one.
CruiserOutfitters.com is an EXCELLENT forum vendor with actual customer service. I got parts for ball joints and repacking bearings here. Call them!
Specifically to your question:
Pads - OEM replacements should be about $65 an axle for OEM. At that price, I dunno why you'd get anything else.
Calipers - if it ain't broke, don't fix it. Just clean it up and flush fluids. If they need replacing (stuck piston, etc), then buy rebuilds.
Rotors - If they are above min thickness and not warped, they are fine. Thickness should be printed on the rotors, or is in the downloadable field service manual. IIRC fronts are 32mm? I could be wrong so SEARCH. If they do need replacing, Centric is a good value replacement.
Front bearings - if it has been more than 30k, or you are replacing front rotors, then do this too IMO. You'll need grease, a couple shim kits, a 54mm socket, an oil seal, a brass drift & hammer, and maybe more depending on what is worn. Again, SEARCH to get educated.
Example result. Then call CruiserOutfitters.
Ball Joints, Tie Rod Ends and/or Sway Bar End Links - this is a good time to do them, if they need done. I assume you know how to check them? If you want to get an idea of what all is involved, search.
Example result. If you need some parts here, CruiserOutfitters again be my first call. They sell 555 UBJs and LBJs that you'll have a hard time tracking down elsewhere, and can point you to whatever else you need.
Hopefully that gets you started. I wouldn't buy anything for this but the grease at Napa.
