These exercises can prove really helpful for beginners in building their speed and the finger muscle strength.
Place your hand on the 6th string with your fingers on frets 1 - 4. Now go through the fingerings below (1 - index finger, 2 - middle finger, etc). Go through them one time on each string. Do this as a daily exercise to build strength and speed. To increase the challenge, play it in the opposite direction after you played it in the normal fashion. Then you can try this on each string to increase the drills challenge even more. To go even farther, you can try it on another set of 4 adjacent strings.
Once you start practicing them, you will find out that its really easy to remember these patterns.
This exercise will work with your picking hand as well as your fret hand by using all the combinations of downstrokes and upstrokes. Below there are two figures given, Fig. 1 and Fig. 2. To do this exercise, you will play Fig. 1 like you did in Exercise 2, but you will use the stroking patterns shown in Figure 2. In figure 2, downstroke is represented by (U) and an upstroke is represent by (V). Don't go with what the letters are, just take them as symbols.
For example: lets take the first pattern from Fig. 1 (1-2-3-4) and lets choose the fifth pattern from Fig. 2 (U-V-U-U). So you would play it together as 1st fret with a downstroke(U), 2nd fret with an upstroke(V), 3rd fret with a downstroke(U) and 4th fret with a downstroke(U) as well. If you have time, play Fig. 1 using all the patterns in Fig. 2, this will truly give you a good workout for speed and endurance.