As I am going to be purchasing a Multi-Family Property this year, should I concentrate on raising the value of my home to maximize the amount I can borrow against a HELOC through upgrading various aspects of the home, or go straight into applying for a HELOC as they will determine market value without an appraiser?

First concentrate on getting to a level of income that allows you a little breathing room so you're not worried about paying next month's bills. 

Your initial screening should be spent eliminating risky applicants and concentrate on those that do appear to fit. 

The entire premise is based on the simple fact that a little effort concentrated on one particular area such as people coming together and helping each other out can significantly affect the rest of the market and the rest of the other people which helps with prices which helps with attitudes which helps with other places to go despite the crime despite the drugs despite the gangs and the turf wars there is hope and there is an answer that would allow everyone to thrive when this opportunity cost type of procedure is implemented. 

Make sure you take investor concentration and the percentage of ownership from one owner/entity into consideration before you make an offer because whether the condo building is warrantable or not will determine whether you can get financing now and in the future. 

@Matthew Jacobsen, pretty familiar with Arcadia but i'm mostly concentrating on North Phoenix and then the suburbs much further out of town.

You should hire someone now so you concentrate on building your wealth and focus on acquisitions. 

I concentrate most of my efforts on the deal pipeline, buyers will crawl over themselves out of the woodwork if you have a deal in hand.

Also, what would you advise as to insurance as this would become my largest concentration of equity with a 25% down payment? 

If you want to stick to wholesellers / MLS while concentrating on flipping, you should aim to try to find something with maybe $10k more spread than this which will be very difficult but not impossible.