Vocals processing

A good rule of thumb is to compress first, then add EQ and f/x.  However, nothing is written in stone.  If you're having trouble getting the vocal to be loud enough, remember, you can always turn everything else down until the vocal sits right.  You really won't be sacrificing headroom.

Here ya go. Part of this article describes using phrase-by-phrase normalization and gain changes in Sonar to do the "heavy lifting" before adding dynamics processing, but of course it applies to Calkwalk by BandLab as well. I also wrote up a similar tip for the PreSonus blog, where I can use more graphics to get a point across than in Sound on Sound articles that cover multiple related topics. The principle is the same for either program.

All good suggestions above, but many of the suggested steps, e.g. applying compression, are for later in the process. You have to start with some coarse leveling and normalization to get in the ballpark, and only then proceed to EQ and compression.
 
When you are your own engineer, it's difficult to monitor mic levels to keep them within a safe-but-hot range, so we all tend to err on the side of caution and be conservative when tracking. This often results in levels that are too low and/or inconsistent. But even the wildest swings in level can still be molded into a steady up-front vocal track.
 
First step is coarse normalization. Play back the vocal track and note its highest peak value. This is to determine how much headroom you're starting with, and to identify which clip is hottest. If it's -12 dB or higher, no normalization is required and compression alone can handle the volume boost. If not, use Process -> Gain to boost it accordingly. You can apply a surprising amount of gain without harming the take. I've boosted vocals by 40 dB without significant noise issues (although those were cleanly recorded in a very quiet room).
 
Next, apply gain to each of the quieter clips so they get closer to the hottest one identified in step one. The easiest way to do this is via a gain plugin that can be automated. I use Blue Cat's gain plugin - it's free, fully-automatable, with adjustable range and the ability to link multiple instances to one automation lane. It's important to do this before applying any effects. If there are any notable "woofs" or sibilance in the performance, you can also use gain automation at this time to mitigate them.
 
It's only after you've achieved consistent volume across the entire track that it's time to apply remedial EQ (as opposed to creative tone-shaping EQ). Talking mainly about high-pass filtering. You want to remove any excess low-frequency energy before the signal hits the compressor. 
 
I'll let others rattle off their favorite compressors and compression techniques. All of the above should happen before you even think about which compressor to stick in.