This post is intended to give some advice to first time Arsenal ticket buyers. Please note, the only official way to get tickets is from Arsenal.com so all others are not guaranteed ticket sites so this post will only cover how to get tickets from Arsenal.com.
First thing you will need is a red membership to have any chance of getting tickets for the majority of regular matches. if you are under 16, get a Junior Gunners membership because it's cheap and it helps you out in the long run as you can go in the family enclosure which has good atmosphere and is cheaper. Red membership is £36 if you want a membership pack, £31 if you don't. JGs is £25.
Tickets usually go on sale to red members a month before the fixture. however, please bare in mind that category A (sp*rs, united, Chelsea and the like) usually sell out before they get to reds. You are also likely to be in the upper tier since the lower tier is usually unofficially silvers only. Midweek games and games not at 3:00pm on Saturday you should easily be able to get tickets for.
Tickets usually go on sale at 10am, while there will be a queue this is the time to get the tickets. Because usually by 1pm most of the tickets seated together will have gone. Once you have your tickets, your membership card becomes the ticket so make sure you take it and your booking confirmation to know which gate you have to go in.
if you miss out, check the ticket exchange on Arsenal.com regularly because often spare tickets do become available.