As techniques have used: Serigraphs on canvas and paper, collage, ballaiage, transfers.
You can have a glimpse at tutorials have written on this.

Starting the creative process
(Some simple facts about painting)

Lesson 1
Some of us when we start, want to paint right away... well that is a major error...
1st you must know how to draw, that's the base of all painting techs. If you don't know how to draw,
perspective, size, depth, will be all mixed up.
You don't have to get drawing lessons to learn how to draw, just pick any material you can think of
and get a "model". By model I mean, your hand, your computer, cat, flower, vase, anything... don't
start with your most cherished one, because it'll be frustrating not to get his picture as you see him/her!
Plan ahead - Ok, you picked for ex. a bottle.... now, get cheap acrylic paint, charcoal, pastels,
conté crayon, sanguine, smooth pencil and cheap non absorbent paper, like scenario paper (sold on roles (?)).
Draw as many perspectives as the bottle allows... top, sides, bottom.
Do it all over with different materials!
If you're a good student, willing to learn and improve your tech., you'll end up with dozens of sketches on bottles!
Now, do the some thing with anything that you want to paint later.... simple things to start with!
Becoming a good "drawer" requires thousands of sketches! Believe me I've been there, and I don't consider myself a great one...!

Lesson 2
Now that you've done your homework; let's get some other things clear...
To became a fairly good painter you need to experiment:
1st - all kinds of paint (start with the cheapest on the market),
2nd - all bases, like paper (non absorbent, like the one mentioned before), canvases, plywood,
anything you can grab...
3rd - you can cut a wood board (big) to staple your papers, so it will be easier to paint...
4th - paint big, that's the only way you can see mistakes and correct them until you get the hang of it!
5th - never draw in pencil, mainly on canvas, pencil always shows up after and you don't know if you want it to show!
6th - black is very tricky, rather use Payne's grey...
7th - don't start with a lot of colors... rather use the basics (red, yellow, blue, white, black, and the one mentioned above), and learn how to mix them to obtain the ones you want.

Oil Paintings Questions and Answers
Thanks to Sharon Galloway (BlackCat) this tutorial on oils was possible.
Why choose oil paints over other types of paint?
Oil Paints are one of the great classic media. They have been used for hundreds of years and have stood the test of time with great durability and steadfast color.
Oils are beloved by artists for many reasons. They offer great versatility. Oils can be very opaque, or they can be thinned with a solvent to varying levels of transparency. They have a slow-drying time, during which their colors do not change, allowing the artist to rework, correct, and even scrape off areas of paint.
What are oil paints made of?
Oil paints are comprised of pigments suspended in a binder, generally linseed oil. Depending on the manufacturer, other ingredients may be added as well, such as stabilizers or dryers.
Which brushes should I use with Oil Paints?
A wide range of brushes may be used. From natural to synthetic bristles, the brush can be left largely
up to the artist. By experimenting with different brushes, each individual artist can find ones that suit their needs.
Traditional oil painting brushes have long handles, so that the artist can work at some distance from the canvas.
The hair is generally firmer and stiffer than for a watercolor brush.
Palette knives can also be a very useful tool for mixing and/or applying oil paints to paintings.
How do I clean oil paint from my brushes?
Cleaning your brushes is a very important step in ensuring a longer life for your brush. In the case of oil paints, the brush should be cleaned off thoroughly starting with solvent and rags or tissue.
Once the brush is fairly clean from the solvent, rub the bristles in a glass or plastic jar with human hair shampoo.
Give the brush a good final rinse and squeeze out any water. Dry the brush with its hair end lower than the handle end to prevent water from loosening the handle and the ferrule. Dry brushes can be stored bristle up in a jar, or laid flat.
What kind of support should be used with oil paints?
Canvas, linen, panels, boards, and heavy papers are all appropriate. It is important that the support can carry its own weight and can support the weight of the paint as well.
Preparing the support is very important. Oil paint must be separated from its support with some kind of ground.
This ground should provide a combination of tooth and absorbency that suit the individual artist.
Below, some common terms associated with oil painting are explained:

"Direct Painting"
This means that the paint is applied in one layer. A good way of thinking about this technique is that a painting can be completed in one sitting, and does not require waiting time before adding another layer.


"Indirect Painting"
This is a more complex method of painting with oils. It is also thought of as a more traditional approach. Here the artist applies many layers of paint, adjusting the opacity of the layers to create different effects. Indirect painting can result in very luminous tones and colors.

"Fat Over Lean"
This is a traditional rule of oil painting. "Fat" paint has more oil in it, and "Lean" paint has less oil in it.
As artists paint layers onto paintings, they make each progressive layer "Fatter" than the one before by adding more medium. The more oil the paint has the more flexible it is. When the over painting is more flexible than the under painting, the paint is less likely to crack as it dries.

"Impasto"
Impasto refers to a thicker application of paint (think Vincent Van Gogh) which has physical dimensionality.
Use caution with this technique as thick layers of paint have a tendency to crack as they dry. Integrating smaller areas of this technique into a painting works best.
How can I protect my finished oil painting?
A finished painting should be coated with a protective varnish. However, it takes 6 months to a year for an oil painting to dry thoroughly enough to apply this finishing layer. In the meantime, store your work in a dust free, but not dark storage area.
Can I save oil paints and use them later?
Once oil paints begin the drying process and have developed an outer skin, they lose some adhesive and drying properties that cannot be recovered.

Here are three tips you can try to preserve leftover paints to use later.
• Try transferring blobs of paint to a strip of glass, then submerge that in water.
• Cover the paint with plastic wrap closely, as to exclude all air.
• Cover your entire palette with plastic wrap or foil and put it in the freezer

My tip for acrylic freaks like me:
If you paint only acrylic but want that oil finish on you work, dont panic, just finish you painting and after drying apply oil glazes on the same colors you painted the acrylic.... you'll notice the difference.... and for those snobish that say "I bought an oil painting", instead of "I bought an art piece" well done, there's their oil painting!

Watercolour Link:
http://www.bigcityart.com/tutorial/index.html
This guys have everything on the matter... as havent been doing it for a long time and there's somebody on the net who's done it nice why not a link? They even have an huge glossery on art stuff!