Stains consist of three components: pigments, dyes and a carrier. The carrier determines whether the stain is oil- or water-based.
Staining permanently changes the wood's appearance, so always test a stain before applying it. One option is to test stain on an area of the piece that won't show--such as the bottom or back. Another is to use a piece of scrap wood for a tester. Because each stain produces a distinctive look on different types of wood, it's crucial to use a scrap from the same wood as the furniture is made.
Stir or shake stain before beginning, as heavier pigments tend to settle in the can.
If the test-piece looks blotchy when you apply stain, you might need to apply a wood conditioner first. If so, apply a liberal amount of the appropriate type of wood conditioner (water- or oil-based, depending on your stain) about 15 minutes before staining.
Apply the stain, making even strokes with a brush, rag or pad. After a few minutes, wipe off excess stain with a cloth. Leaving the stain on longer usually yields a darker color.
Once the entire piece is stained, let it dry overnight. Apply more stain if you wish to darken the wood further. As it dries, the stained finish may take on a dull look. A fresh appearance will return when finish is applied later.
Also i think you may find its not oak but Birch thats seems to be the only unfinished ones they sell.
The bubbles most likely is applying too much at one go.