First of all, I am assuming anyone who is reading this is a well versed musician and has a steady band with many songs at their disposal. The music scene is hard enough to get onto without not knowing what you're doing musically.
Second of all, when I refer to the "music scene" I am simply referring to the local music scene. I'm not going to give advice on how to play Warped Tour because I haven't accomplished that deed yet.
Thirdly, the older you are, the easier it is to find gigs. You're taken more seriously and when you're 18, it makes it easier to play in bars.
Step I: Organizing Your Band
1.) While, it may go against the democratic process so ingrained in our society and may hurt some people's feelings, you need to elect a person to be the spokesman for your band or find a band manager. Having one person to talk to means that local venues and the like only have to deal with one person. It makes negotiating prices easier and it puts a face on the band. Trust me, it may seem harsh or hard to elect a band member, but it's that or a band manager.
a) Band managers- doesn't mean your friend who can't play music. A good band manager should already be on the scene. So for instance, if you know a drummer who has been playing around town for a year or so with his band, talk to him to see if he would be interested in managing or if their manager/leader could manage your band. You can negotiate the price if that's what it takes to gain a manager, but some people are just happy to be part of something.
2.) Define your genre in 3. It's best to ask other people what you're sound is. If you're striving for grunge, but you're playing punk, then you need to know that, and playing what you mean to play is harder than it looks. Also, settle on a band name if you've not established one yet. But it really doesn't matter. The band name should represent what you play, but it doesn't really matter. Just something original. It's really not that important.
3.) Set up guidelines. A band (even if you're all 16 years old) is a job and a (dis)functioning system. For instance: make it known to the band manager and your band-mates that you can only miss 5 band practices. By setting up guidelines, you're pushing on a role to other members of your band and they know the rules.
Step II: Pre-Gigging
1.) Develop a solid set-list of about 20 songs that can be interchanged. Originals are great and all, but covers typically define the music you play, and at an earlier stage, it's important to establish a definitive genre. So divide up the set-list, maybe about one-third originals and two-thirds covers. But pick covers that match your genre. (Early on at least)
a)Make sure that your songs are perfect before you even start.
2.) Organizing your may set-list may seem unimportant, but it's probably one of the most important things you can do. For instance, go watch a local band (or a famous one). Notice how the first song is typically super energetic or at least catchy. A good set-list will open strong, and cascade down into mellower stuff, with an occasional spike in energy. Keeping the crowd entertained is your primary goal, because, as a guitarist in one of my bands said, "Musicians play and are also entertainers." Keep the crowd on their feet.
3.) Getting a basic eq/sound level is actually pretty simple. Set up your band like you would play a gig. Play a solid song and have the drummer just start it like he normally would. (Playing at small/medium gig levels) Enter the bass. The bass should be audible over the drums, yet mix into the bass drum. A keyboard/piano/organ comes in now. Depending on how it sits with the band (lead or rhythm styled playing), it needs to be EQ'd accordingly. But remember, you're eq'ing about 7 octaves of range. Have the rhythm guitar come in next. He should be solid and audible, yet not not flashy. Lead guitar comes in next. Boosting mids helps here (yes, even for metal) because it cuts through the mix easier. More volume doesn't mean you'll cut through by yourself. It takes proper eq. Remember, the bass crunch you've got going on when you practice by yourself can be trimmed down because there's already a lower frequency. Treble can be boosted, as can the mids, because they aren't as frequency in the mix. Vocals should come in next. They're pretty hard to eq unless you've got a nice PA system typically because it will feedback. But mids are a must here, so is treble. (It takes skill to remove the annoying "pop" of "p"s.)
4.) Sound-check before every single gig. That doesn't mean 5 minutes before you're on. Try to get there sometime in the afternoon to set up. Any venue worth its salt will have an in house PA normally with a sound technician. Utilize the spare time to get your sound right. But you shouldn't be using this for practice time.
5.) Identify venues that are your target audience. A jazz/piano bar isn't good for a grunge or metal band. You can tell typically be the people in the venue itself.
6.) Recording demos are extremely important. A demo should have 3 or 4 songs that represent all corners of your band. (As in, a mellow song, energetic, fast, slow song in the same genres) Even if it's just a shoddy garage band session (the music itself should be solid) burn it to a disk and have your manager go around at some point and give a disk away to every bar you've possibly identified as a venue you'd like to play. Act respectful and look presentable. Leave them a call back number. Do not discuss prices until after they call you back. Remember, it could be 5 weeks after you give them the disk when they call you back.
7.) Remember. You're entertainers. Entertainers need to be able to observe and respond to their audience quickly. If they're having an awesome time, running around and head banging, meet their enthusiasm with more! If you're playing at a venue where you're more of a background, then sit down and be mellower.
a.) This also means, knowing how to act and dress based on the music you play and the venues you play at. Yes, yes. I've heard the whole "expressing yourself" line several times. But, remember your not playing Wembley Stadium. So it looks goofy getting in your leather chaps and not wearing a shirt when you're playing small gigs.
Step III: After Your First Gigs
1.) Keep playing. Never turn down an opportunity. When I first started gigging, me and some friends got invited to play the first bi-monthly local youth musical festival called "Barnaroo" (played in a barn) because we knew the people throwing it. Even after playing one of the biggest venues in my town, I'll still Barnaroo because you never know who's watching or who is interested in your band.
2.) It's important to keep your ego in check and fame in perspective. When people get cocky is when the ship goes down. Be modest, respectful, and helpful, even if you're the biggest name in your town.
The steps listed above are everything that I've done, my friends have done, my guitar teacher, etc. have done to get on the scene. Remember, it takes time and patience to get your first gig. Thanks.