You have a computer and a mic.  Good start. 

Now you have to consider your workspace, both at home and mobile.  Your home-studio and mobile setups will need to have monitoring (control room) and recording (studio) capabilities.  You can monitor through anything from headphones to expensive speaker and amp systems, and record anywhere that is quiet enough and gives you the acoustics you want.

Often mobile solutions work effectively for low budget studio solutions.

For example, you can have a studio setup that has a separate special quiet vocal booth that deadens extra noise and echoes, allowing you to capture an intimate vocal sound.  If you have to record a vocal in someone’s house you may have to record with the person standing in a closet for a similar effect.  You may need to suspend blankets around the person if they are in an open room or even ask them to perform under a large coat if needed that particular isolation and had no other options.

In your studio you will be able to work with your space to increase your recording options and sound control.  You should set up your speakers in an area that sounds somewhat dead rather than full of echoes or natural reverb. Hard surfaces such as windows, flat uncovered walls and wood or tile floors will reflect sound and create a more echoed and reverberated area. Hanging sound absorbent fabric or other materials (cork, egg cartons, etc) can help to deaden an area.  The more sound absorbent surface area you create more dry the area will sound.  Cardboard egg crates mounted with the rounded dome parts facing out into the room will absorb more sound than flat pieces of cardboard.  Even bookcases filled with folders and papers can help to dry up the sound of a room.

If you do not have the luxury of being able to design and build from scratch, you may have to move your speakers to a few different positions before finding where they sound best in the room you monitor in.  Try not to position speakers against walls as the wall vibrations and reflections will affect the sound. 

Your recording area should be large enough to accommodate your musicians and their instruments.  Start by finding a good place to put the drums so they sound even and full in the room.  Some parts of a room may sound brighter and bring out more cymbal splashing, and other parts of a room may add more warmth and depth to the drum sound.

Once the drums are set, place the other instruments in a circle, with as many elements facing each other as possible (like numbers on a clock).  This will allow each person to be able to see and hear everyone else.  In addition, if the sound sources (guitar amps, drums, etc) are facing each other then it is more likely that you will have less sound leakage as they are more in their own “acoustic space”.

Instrument acoustic spaces can be further isolated from each other by placing sound absorbent objects or partitions in between them (like lines between numbers on a clock).  This theory of isolating different sounds to control sound leakage is carried out to the point of having individual sound proof booths for each musician.  Regardless of how much or how little isolation and leakage you are concerned with you must make sure your musicians can see and hear each other well enough to create their music as a GROUP rather than isolated INDIVIDUALS.