Spreads are a means of laying out the cards to do a reading. A number of cards are selected by various methods of shuffling, cutting or random selection of reader or questioner. The cards are then usually place in a specific pattern in which the reader intuits specific information pertaining to the person's need. Some believe that a true psychic doesn't need to do specific spreads and can read from any patterns of selected cards.
The following are a few examples of Tarot spreads and what they represent.
3 Card Spread
1.
2.
3.
5 Card Direction Spread
1.
2.
3.
4.
5..
4 Card Attainment Spread
1.
2.
3.
4.
1 Card Spread
1.
Can be used for various questions.
Yes/No
Meditation
Card of the Day
Speak to Me
What time/month/year/season
Cards are read in both upright and reversal positions. It is usually up to the reader. Most authorities say that reading without reversals gives only some of the story. Reversals can definitely be seen as blockages, but some cards offer positive no matter which way the are turned. If read intuitively versus mechanically, the reader should be able to tell where the blockages or gray areas are with or without reversal.
I prefer to use my own interpretation of spreads but there are many excellent resources to investigate on the subject.