Be sure to start by going through the Steps to Study Abroad  section of this web site. It outlines the process and describes how study abroad works.
Also check the section on Major Advising Pages  to see if one has been created for your major already. If so, you’ll find some good tips on what kinds of classes can easily transfer from abroad and also view a list of suggested programs that offer relevant course work for your major.
As you contemplate where you would like to study in the U.K., many factors come into play.
A decision tree
First, you’ll need to select a site that offers the classes you need to continue to make progress toward your UI degree. That can be relatively easy if you have lots of flexibility about your schedule, for example, if you still need to finish up some General Education requirements, need electives, and/or need major credit in a subject area that is commonly taught in the U.K., such as humanities, social sciences, science, and engineering. Selecting a site can be much more challenging if you need to get very specific classes during the semester you are abroad, for example, if you are a senior in the health or biological sciences, or in engineering. Sometimes a short-term summer program is worth considering in these cases.
Second, you need to consider how much you can afford to spend on study abroad. If you are fortunate and have lots of financial support, a semester or year in London -- or at an elite British university such as Oxford, Cambridge, or Edinburgh -- is a possibility. If cost is a large factor in your decision, you will probably study in a smaller community, or for a shorter length of time. (You don’t have to live in London to take advantage of the city. There are many locations within a 2 – 3 hour train ride that allow you to spend weekends there.)
Third, some students think they should base a decision on where to study abroad on how easy it is to travel from their site to other places in Europe. Study Abroad discourages decisions based on this criterion for several reasons. For one thing, the U.K. is not that large, and getting from one place to another doesn’t take that long. One doesn’t need to live in London in order to fly out of Heathrow or Gatwick to the Continent. And, Europe has become incredibly travel-friendly with the creation of several no-frills airlines (such as Ryan Air,  Easy Jet , or German Wings ) that operate between major cities. You often do not need to travel to London in order to fly to other cities in Europe. Another reason we discourage this line of thought is that students often overlook what is in their own back yard when they study abroad. They think they need to visit every European capitol city during an academic break and end up learning as much or more about airports and train stations as they do about the places they visit. It can be wonderfully exciting and fulfilling just spending some time “in the neighborhood” on a break, or if you are fortunate enough to make friends with a British student, visiting her or his home and meeting the family during a weekend or break. The U.K. is a stunningly beautiful place with no end of things to do. You do not have to travel far to travel wisely.
Now, consider some of the “watershed” decisions you need to make about studying in the U.K., as described in other sections of this self-advising manual, including
In London or Not 
The UI offers study abroad programs throughout the U.K., some lasting as little as two weeks and others an entire academic year. Our short-term programs tend to focus on London and are faculty-led, “island” programs. We turn London into a learning laboratory and exploit the city’s cultural or business connections. Our semester and academic year programs are located outside London and are all based on the “direct enrollment” model. We partner with British universities that offer comprehensive academic programs in a variety of subjects and specialties. We locate our semester and academic year programs outside of London primarily as a cost savings to University of Iowa students. It is one thing to live in London for 2 – 6 weeks during the summer, but another to spend a semester or a year there, the cost of living being what it is. UI students tend to be from smaller, rural communities, too, and living in a city the size of London can become wearing.
Study Abroad frequently receives proposals from UI faculty for new study abroad programs, and the list above may change.
Iowa Regents Semester in Wales  (University of Wales Swansea)
Iowa Regents Semester in Scotland  (University of Edinburgh)
Semester at Queens University Belfast  (Northern Ireland)
The U.K. Exchanges
University of Strathclyde Exchange 
University of Lancaster Exchange 
Hull University Exchange 
University of Birmingham Exchange 
The University of Iowa does not require its students to go on programs offered by Study Abroad. You can study on other U.S. university programs, or enroll independently in a British university. Thus, if there is a compelling personal or academic reason to study in a location where the UI does not have a program, by all means explore that possibility with the help of a study abroad advisor. We want to help you find the best “fit” for your needs, be they academic, personal, or financial. The Study Abroad Resource Room is a great place to start looking.