The best overall source for Pathfinder character guides is Zenith Games' Comprehensive Pathfinder Classes Guide, which links to multiple Fighter and Ranger CharOp (character optimization) guides with sample builds. For builds in general, Paizo's NPC Codex is one of the best books ever and has a bunch of interesting fighter and ranger builds of every level (and Hero Lab has it as a data pack, woot!). Those tend to be more modestly optimized, but probably do a better job of showing the kinds of PCs that Paizo expects in their adventures.
However, you should stop to consider before doing that. High levels of character optimization bring a lot of problems to groups and GMs. If the players are happy with their own builds, trying to get them to "up their numbers" isn't necessarily welcome. Let them play the way they want. As the GM you can control the power of encounters they hit, so if they can't handle CR=level+3 encounters, just don't do that. With published adventures the CRs are set but you can easily control the rate of advancement - go to fast advancement and then non-optimized characters can meet the printed challenges (there's obviously 10 other ways of finessing that but that's the most basic). Paizo modules tend to assume non-super-optimized characters, as their sample iconic characters should make clear.
If they are veteran players, they likely know they could optimize and are choosing not to. You should get on the same page as they are with game expectations and then run the game the group wants. My recommendation is to take a couple sample characters to them and say "hey, you know in Pathfinder/3.5 you can make uber builds with really high damage" - and then either they say "Really? Awesome I love me maximizing my DPS, let's do it," in which case yay, except that then you have to figure out how to run for a super-swingy glass cannon high CharOp game. Or they look at you like you're a deviant, in which case you should rethink your life choices and play a non-op game!