As a person who has worked in a marketing department ill give some advice.....
1st make a reconisable brand name...that should include the movie and your production company.
2nd as people said network!!! its free and it works...use youtube (some clips of a exciting scean..and a preview or 2 or even a music video if you have some orginal music) facebook and twitter...these are standerd marketing website tools that ALL!!!!! business use. Dosent matter what they sell thoes 3 sites are standard! but make sure when you launch to update posts/blogs alot! Also contact a local paper about your film..most towns and citys like to write about hometown peeps doing cool things..(unless your in hollywood..these is no chance for a write up there!)
3rd Know your audience. If its scifi then see if there is a local scifi con to preview or even preimer your movie. you need to get the word out and these conventions are great ways to interact with your audience...if its cheep enough get a table at the dealers room. Also contact local comic book stores and other brick & morter store that may buy a few copies...but you need to find and try to interact with your audience.
4th online stores amazon and such are taking over and netflix with their dloaded movies even more so! contact these places to see if you can get the movie on their sites.
5th yes a good website is needed! look around and research which websites are getting alot of traffic. take the best elements and make them your own.
6th if people offer free art work i would look into it, but be warned! you need to be specific on your vision! just dont take any art work. if you dont like something speak up. all said and done you are the boss. If you dont like it ..well u dont like it! take charge..be open to suggestions ..but stick to your guns a little.
