Most bands begin in pubs playing to a very small audience earning zero fee. You should go and meet gig venues and offer to play a gig and emphasise that you will promote it yourselves. An Email is simply not enough and more often than not you will get no reply. Visiting the venue shows that you are serious and this will secure you many bookings.
When you are starting out the experience of playing live, dealing with your PA system and getting the sound levels right for your performance is an essential part of being a reliable and quality live act. Pad out the audience with friends and family and take constructive feedback on your performance from the venue owners. Hopefully they will invite you back and tell their industry colleagues in other venues what a great idea it would be for them to book your band for a gig.
Common sense is the way forward in terms of your PR. Contact the local press and invite them to attend each gig but do not get too pushy with them as they get many invites of this nature. It may take some time and many requests before a reporter comes to your gig. Hopefully if you keep asking, eventually they may have a free evening and come along. At this point you must have the talent to impress them.
Send out well-written press releases to local music websites, magazines and local events portals with a high resolution photo they can use as a thumbnail or avatar for their listing or article. This makes it easy for them to create an article in a short amount of time which increases your chances of getting exposure.
Another good idea is to provide small leaflets for the venue in advance and ask them to distribute the leaflets to promote the event. It is in their interests to get customers into the venue so they will often be receptive to this type of promotion. Let the local youth club or youth organisation know you have a gig as young people love music and are often looking for things to do in the evenings.
There are many social networks dedicated to music and you should have a web page on all of them, particularly the larger ones. You should add photos, video, event information and connect with other users who will hopefully love your music and become your fans. Having these pages helps create a really professional feel for your band and make you look very established. Mailing lists are fantastic for getting the word out about a gig or a new music release. The social networks can store playable mp3s of your band performing and videos of your performances. Ensure that any media you use whether audio or video is good quality or you will make yourselves look like amateurs.
Do not fall into the trap of thinking you are better than you are. There are thousands of bands out there and plenty of options for a venue owner that you offend either by accident or on purpose. Remember the worlds biggest and best bands can get away with bad behaviour because they guarantee big money and are in high demand. The majority of bands are easily replaceable if they prove too difficult to work with!