No problem, I'm always glad to help in what way I can. When you first start trying to play lead, it can get really frustrating, so stick in there and you'll start seeing the results you want to see in time. Music theory will really help you with composing songs and solos in ways that I dont think I can even explain. The more theory you learn, the more questions you'll have, but at the same time, the more knowledge there is, the more you can start to comprehend how music works. When you get deep into theory, you can really understand the relationships notes have with each other, thus allowing you to understand why certain chords sound like they do, etc. etc.
Music theory can be very confusing, but if you take it a bit at a time its not too bad. The very first thing you should start with would probably be learning about your basic scales. Although they dont all sound very "Heavy Metal", you need to know your major and minor scales in order to understand just about anything else in music theory.
Most scales have seven degrees, or steps. (Pentatonics have 5) The pattern for major and minor scales is pretty simple. In a major scale, each note has a whole step difference between that and the next note, except 3-4 and 7-8, which are half steps. Note: the 8th note of the scale is really the first note, an octave higher. So if you write this out in a C major scale, it looks like this:
C D E F G A B (C)
1 2 3_4 5 6 7_(8)
C major works out perfectly, without any sharps or flats. Other scales will have at least one, however. A half step can be acheived either by making a note sharp or flat, or by the natural half step difference between B-C and E-F. The difference between B and C, and the difference between E and F is always a half step, whereas anything else, like the difference from A to B is a whole step.
(Sharps are written as: #
Flats are written as: b )
Lets look at G major as an example of how to apply half steps.
G A B C D E F#
1 2 3_4 5 6 7_
Since we're playing a G scale, we start on G. This is the root note. After G, we have A as the second degree, and B as the third. Now, remember that in a major scale, the distance betwen 3 and 4 must be a half step. Fortunately for us, B is the third, meaning C is the fourth. Since B-C is always a half step anyways, we dont have do anything. D is the next note after C, then E, and F. The distance between 6-7 is a whole step. However, from 6 to 7 we have E to F, which as you remember, is a half step. This means that in order for the pattern to work, we're going to have to change F to make the distance between E and F a half step. We do this by changing it to F#, one half step higher than F.
If you didnt already know this, one fret is one half step. So a whole step, such as F to G is a distance of 2 frets. A half step is a distance of one fret. So tabbed out, it looks like this:
Whole steps:
E|-1--3--5--7-- etc.
Half steps:
E|-1--2--3--4--5-- etc.
So heres what a G major scale might look like when tabbed out:
E|------------------------------------------------3--5--7--5--3--
B|--------------------------------------3--5--7------------------
G|----------------------------2--4--5----------------------------
D|------------------2--4--6--------------------------------------
A|--------2--3--5------------------------------------------------
E|--3--5---------------------------------------------------------
Note that on the 6th string, the low E, we started on G, even though E is the lowest note you could play in that position in the scale. In general, you would start on G, like we did, and end on G as well, because it's a G scale. I didn't tab out descending back down the scale because I figured you get the idea already.
One thing to realize about the relation to major and minor scales is that a major scale contains the same notes as its relative minor, but since it has a different root note, you start or end differently. To fully understand this, you'll need the formula for Minor scales:
Half steps between 2-3 and 6-7
Emin is relative to Gmaj, meaning that they contain the same notes.
E
F# G A B C D E minor
1 2_3 4 5 6_ 7
G A B C D E
F# G Major
1 2 3_4 5 6 7_
So E minor and G major have all the same notes, but they start and end at different points. Why is this significant? This will be more important later, when you learn about Tonic, Dominant, and Subdominant areas, or composing for two guitars, but right now what this means is that a solo in G major will emphasise G, while a solo in E minor will emphasise E. One way to do this is by ending on those notes.
By the way, E minor is one of the most common scales for metal / rock, probably the easiest and most common to write. Keep in mind that a pentatonic is based off whatever scale you derive it from. So if you have a chord progression in E minor, you can deffenitely solo off of that in E minor pentatonic. Pentatonics just cut corners a bit, having 5 of the 7 notes you'd normally have.
Tell me if you have any questions, or if you want more to work on. It's important that you develop a really good understanding of these rudimentary things. One good way to boost your understanding is by figuring out scales yourself. Note that not all scales are possible. For example, there is no G# major. Heres a list of scales that do work, however.
Major
C
F
Bb
Eb
Ab
Db
Gb
F#
B
E
A
D
G
One formality to remember when writing this out is that E and B arent ever sharp. Instead of E sharp you would write F flat. Its like the difference between 1+1/2 instead of 2 - 1/2.
HI Living to die! Finding a solo is quite simple. First, you must know the harmonic structure of the backgroud music of your solo. Which means the 
