Hey Excelscia! Welcome to Res. c:
As for your questions, I have the answers! [Thankfully.]
Can you dress your pet?
Unfortunately no, that is not an option here on Res. BUT, there are so many cool designs and colors, etc, that you don't really NEED to dress them up!
Where can you find prices on items/pets you want to sell without under/over pricing?
For items you want to sell in your Merchant Shop, there is an 'Item Database' under the Information Tab on the top of the page. If you type in the item name, it will give you the average price that specific item sells at, and what the last few items were sold at in the shops.
-As for pets, also under the Information Tab, you can click 'Creatu Search'. Here, you put in the information about the pet you want to sell [Make sure you're looking in Rancher Shops only!] and see what other users are selling their creatu for!
If there are NO items/creatu in shops, feel free to ask the more experienced users in the Shout Box or Rmail someone about it! Res is extremely open to helping new, and even older, users with the site, and don't hesitate to ask. :)
Can a pet die if it isn't fed?
Yes! SO FEED YOUR PETS. If you won't be on for a while, or are just lazy [Like I am .-.] there's the food pen! This handy service allows you to put as much food as you like, to your upgraded limit, and it will feed your pet when its hunger gets below 70. Very convenient in my opinion. Just don't forget to re-stock this as well, as I have done plenty of time. xD
Are there any guilds?
Nope, not on Res! There were once Parties, which may be coming back in the future, which were similar in some ways to guilds, but aren't exactly the same thing. But, for the time being, there are no guilds or parties to join.
Hope this helped! If you have any more questions, concerns, etc, feel free to Rmail me, or a user who's name is pink [it's their job to help new users. c:], or the sb for help!
Hope you enjoy your time on Res! <3