Sean... Welcome to the BP family! I am located in Pennsylvania, specifically the Lehigh Valley, and I focus on value-add Multifamily...Here are few things to check out as you work your way around the site. Below that you'll find more answers to your questions
Find and connect with other BP members that are in your area: https://www.biggerpockets.com/search/users
Set up some keyword alerts to notify you when members are discussing something that interests you. I use this a lot for location based discussions: http://www.biggerpockets.com/alerts
Read Beginner’s Guide: http://www.biggerpockets.com/real-estate-investing
Check out the BP Podcasts. There's tons of great info in these: https://www.biggerpockets.com/podcast
Determining the ARV is going to depend on the property type of which you're looking. If it's a commercial property the property value is determined by it's Net Operating Income (NOI) and Cap Rate. The Cap Rate is determined by the type and condition of your property in your particular area. If you're looking at a residential property (single family home or multifamily with 1-4 units) than your ARV will be determined based on comps in the area. What I do in those situations is look up comparable properties to mine on the MLS or Zillow and see what those comps are currently selling for. This will give you an idea of what your property will sell for after rehab.
To estimate your repairs I would recommend either contacting a local contractor you can you trust to help or buy The Book On Estimating Rehab Costs by J Scott. BP is actually running on special on that right now I believe. I have it and it's awesome
Vacancies will vary per area...a quick internet search for your particular market will help with this but as a rule of thumb you can budget 10% of your property's income
CAP Ex and Maintenance can also vary depending on how much work you put into your rehab on the front end, but be conservative with your budget so you don't get caught with a costly expense you're not expecting. Again a good rule of thumb is to appropriate 10% of your income. I use 10% for both CapEx and Maintenance combined.
I hope this helps and let me know if I can help you with anything else. Good luck