My random thoughts on the subject:
I'm not an actor and the only stuff I know on the subject comes from whatever dealings I have had with working actors.
An approach that can help you get work is to typecast yourself. If you have a look and a type of character you can play well, while you might not get a broad range of roles, you are more likely to get cast because you fit what a casting director is looking for. Character roles tend to get you more work than trying to get leading roles.
The key job of an actor is to be able to communicate emotional states and intents. On one hand you might think that this would be the worst job for an Aspie, but I think in some ways an Aspie might be well suited to this job if they were particularly observant. In some ways an Aspie might do better because their own emotions may not confuse how they perform a role.
Most successful working actors also hold other jobs. I am currently trying to buy a house and my real estate agent is an successful actor who you've probably seen on a number of TV shows. Some of the researchers or producers I work with in my job are actors who I see from time to time on various shows. If you go into the job knowing it won't pay all your bills, you stand a better chance of surviving the difficulties of that kind of work.
Do not try to become an actor by starting out as an extra. Extra work is fine, but it won't get you acting work except in odd rare instances. One of the odd union rules in some situations is that directors are not allowed to talk to extras. If they do, the extra is paid more. So extras are often treated more like warm fleshy props rather than people. (It's the assistant director who directs the extras)
If you want to get work and keep getting work, make it easy and pleasurable for people to hire you. (This applies to any field) Get a well done head shot and make sure all your contact information is clear and obvious. If you do get a job, show up early, do the job well and don't get in the way. Make sure you are available for reshoots etc. If you create a problem for a casting director even once, there is a strong chance they will not hire you again. But if you made them look good they will want to keep working with you.
Find a way to stand out. Some actors achieve a particular look that gets attention or a specific kind of character. Harry Dean Stanton usually plays haggard but likable people. Laura Linney tends to play highly competent women. (Although she played very much against her type in "Savages" which worked well for the character.) Look at some of the performances in the earlier Coen Brother's films or early Spike Lee films. A number of actors seemed to get their careers launched from these films. I think a lot of the reason why was that not only were they very good performances, but the characters stood out and were memorable. When casting directors saw these films, they remembered the character and the actor who did it.
Being weird is a good way to stand out but it can also limit you. Crispen Glover seems to have come and gone. It can be useful to have a head shot where you look your best in a conventional way, but you might also consider a head shot where you push it toward a more extreme character look. In putting together an actor's reel, look for scenes where you can show clear attitude and character's intent. Scenes like the "Hertz Donut" monologue from "The American Astronaut" might be a good example. I had never heard of Tom Aldredge before but I won't forget him after that scene.
[youtube]http://www.youtube.com/watch?v=HLZ9rTzLURw[/youtube]
or Joe Pesci's "Funny, How?" scene from "Goodfellas" (I'm certain it was this scene for which he won his Oscar)
[youtube]http://www.youtube.com/watch?v=o_ff46b58Hk[/youtube]
I guess my point here is that a key to getting work is getting remembered. Some people get remembered because they climb up a tower and start shooting at people, but their value to society is somewhat limited. But creating a character that is interesting and memorable can help you get acting jobs.
Hope this helps,
Lars