Many old documents were written out longhand, and if you're lucky to have access to records like this, you may have a challenge to actually read what they say.
As I continue to transcribe this interesting old will of Thomas Church (dated 1635), I'm getting a better feel for the old style of handwriting. It dawned on me that there might be some illustrations or other resources online for reading old English script.
I have found a few good places that have illustrations and examples of various forms of medieval English handwriting, including some helpful notes and information on how things were written and phrased during that time. I am still very surprised that handwriting is so different compared to modern day.
Now remember, there is more to translating old documents than just the handwriting. The spelling may be "creative" and there may be obsolete terminology that you don't recognize. My own will refers to his "wyffe" on more than one occasion.
National Archives Palaeography - This is a great site to start understanding the nuances of English handwriting between 1500 and 1800. There are some fun interactive tutorials, where you can attempt to transcribe pieces of old documents. Each tutorial document links to a full alphabet for comparison. There are several good tips on understanding numbering and dates as well.
Transcribing Secretary Hand - Secretary Hand is the term used for the style of script you are most likely to come across, from the Tudor period. A few examples are given for each letter, in a printable chart form where you can then fill in the letters from your own document for comparison.
English Handwriting 1500-1700 - A very handy set of alphabet comparisons. Click on any letter, in either upper or lower case for several examples of handwritten letters. I recommend this site for strictly translation use.
Dictionary of Genealogy & Archaic Terms - As I mentioned above, half the battle is understanding the words as well as the handwriting. Here is a helpful (though not recently updated) dictionary of all kinds of terms that you might come across. I found two oddballs that had been puzzling me: burgage and messuage (both terms used to describe pieces of land). I will definitely be going over this list with my will in hand at my next opportunity.
My biggest suggestion is to not give up when reading through a hand-written document. Take it one section at a time, and make sure you have plenty of light. You will get a better feel for your particular writers script if you make an alphabet comparison chart of your own as you go. It's easy to forget that you actually know what a certain character is, after reading many lines of strange words.